Human epidermal Langerhans' cells are targets for the immunosuppressive macrolide tacrolimus (FK506)

Treatment of immune-mediated keratitis (IMMK) in dogs with immunosuppressants observed with spectral domain optical coherence tomography (SD-OCT)

Two dogs presented with bilateral pattern-forming corneal opacity. Treatment with topical immunosuppressants was initiated after a complete ophthalmic examination. The response to treatment was assessed by analyzing serial images using slit-lamp biomicroscopy and spectral domain optical coherence tomography (SD-OCT). Both dogs responded to topical immunosuppressants; however, the lesions recurred once the treatment was abated or withdrawn. The most effective immunosuppressant in both dogs was 0.03% tacrolimus ointment. Early and continuous treatment with topical immunosuppressants may be necessary to improve corneal clarity and prevent scarring. SD-OCT could provide useful structural information regarding presumed immune-mediated keratitis and aid in monitoring treatment response.

The Efficacy and Safety of Pimecrolimus in Patients With Facial Seborrheic Dermatitis: A Systematic Review of Randomized Controlled Trials

Facial seborrheic dermatitis (SD) is a chronic inflammatory skin condition that can affect the quality of life with frequent recurrences. There is no medication as yet to cure this disease completely. There are four general categories of agents that are used to treat SD: antifungal agents, keratolytics, corticosteroids, and lastly calcineurin inhibitors. Topical therapies are the mainstream line of treatment to be used for this skin condition.

The objective of this article is to critically review the published data in the literature on the use of topical pimecrolimus 1% topical cream as an option for treating facial SD. The final purpose of this review is to answer two questions: whether pimecrolimus topical cream is effective for the treatment of SD compared to the conventional current treatments and how safe is this treatment. 

The PubMed, Clinicaltrials.gov, MEDLINE + Embase, and Cochrane library databases were searched for original randomized clinical trials (RCTs) evaluating pimecrolimus 1% topical cream and comparing it with other topical treatments for SD. A systematic review and meta-analysis were then conducted on the selected studies by grading the evidence and qualitative comparison of results among and within studies. A total of five studies were included in the review; however, only four were eligible for inclusion in the meta-analysis, in which pimecrolimus was compared with other treatments for the management of facial SD.

Pimecrolimus was found to be an effective topical treatment for facial SD, as it showed considerable desirable control of the symptoms in patients with facial SD clinically, in addition to a lower recurrence or relapsing rates; however, it had more side effects compared to other topical treatments, but the side effects were mild and tolerable.

Itchy Toxicodendron Plant Dermatitis

Plants such as the Toxicodendron species, consisting of poison ivy, poison oak, and poison sumac, largely contribute to allergic contact dermatitis with itch as a predominate symptom. Many individuals are affected by this skin condition, with approximately 50% to 70% of adults in North America demonstrating a degree of clinical sensitivity to this species of plants. In this review, we discuss the prevalence, pathophysiology, and clinical features of this contact dermatitis, as well as both treatment and prevention directed towards alleviation of itch. Updated research is emphasized throughout this review, although it is evident that this field is evolving, and more research is necessary to enhance treatment.

Practical algorithm to inform clinical decision-making in the topical treatment of atopic dermatitis

Atopic dermatitis is a chronic relapsing, inflammatory skin disorder associated with skin barrier dysfunction, the prevalence of which has increased dramatically in developing countries. In this article, we propose a treatment algorithm for patients with mild-to-moderate and severe atopic dermatitis flares in daily clinical practice. An international panel of 15 dermatology and allergy experts from eight countries was formed to develop a practical algorithm for the treatment of patients with atopic dermatitis, with a particular focus on topical therapies. In cases of mild-to-moderate atopic dermatitis involving sensitive skin areas, the topical calcineurin inhibitor pimecrolimus should be applied twice daily at the first signs of atopic dermatitis. For other body locations, patients should apply a topical calcineurin inhibitor, either pimecrolimus or tacrolimus, twice daily at the first signs of atopic dermatitis, such as pruritus, or twice weekly in previously affected skin areas. Emollients should be used regularly. Patients experiencing acute atopic dermatitis flares in sensitive skin areas should apply a topical corticosteroid twice daily or alternate once-daily topical corticosteroid/topical calcineurin inhibitor until symptoms improve. Following improvement, topical corticosteroid therapy should be discontinued and patients switched to a topical calcineurin inhibitor. Maintenance therapy should include the use of pimecrolimus once daily for sensitive areas and tacrolimus for other body locations. This treatment algorithm can help guide clinical decision-making in the treatment of atopic dermatitis.

Topical Tacrolimus in Thygeson Superficial Punctate Keratitis

PURPOSE

To evaluate the efficacy of topical tacrolimus 0.02% eye drops in the treatment of patients with Thygeson superficial punctate keratitis.

METHODS

Ten consecutive patients with Thygeson superficial punctate keratitis were included retrospectively. Seven patients were unresponsive to topical steroids and/or lubricants. Diagnosis was made based on the history and clinical findings. All patients were treated with topical tacrolimus 0.02% solution twice daily. Outcome measures included improvement in symptoms of tearing and photophobia, whereas improvement in signs included decrease in the number of the lesions, resolution of the lesions, flattening of the lesions, and decrease in stain of the lesions.

RESULTS

There were 3 male and 7 female patients with an age range of 3 to 51 years (mean 17 years). All patients had bilateral ocular involvement. Duration of treatment ranged from 1 to 42 weeks (mean 10 weeks). All patients had subjective improvement in symptoms of tearing and photophobia and resolution of the superficial punctate keratitis. The response to treatment was noted 72 hours after initiation of therapy in all patients. Topical tacrolimus was well tolerated in all patients.

CONCLUSIONS

Topical tacrolimus 0.02% is safe and effective in reducing ocular surface inflammation in patients with Thygeson superficial punctate keratitis who are not responsive to conventional therapy. Tacrolimus is helpful as a steroid-sparing agent to avoid vision-threatening complications.

Practical Recommendations for the Topical Treatment of Atopic Dermatitis in South and East Asia

Introduction

There is some evidence to suggest that the prevalence of atopic dermatitis (AD) in Asia is rising. We have therefore developed an algorithm for the topical treatment of AD throughout South and East Asia for use by primary care physicians, pediatricians and dermatologists.

Methods

Nine AD experts from South and East Asia and one from Europe developed the algorithm based upon treatment guidelines, relevant literature and local treatment practices. The algorithm outlines current best practice for the use of emollients, topical corticosteroids (TCS) and topical calcineurin inhibitors (TCI), with the intention of simplifying the treatment regimen of mild-to-moderate AD in South and East Asia.

Results

Patients with AD should bathe and cleanse affected skin to remove crusts and scales daily. Emollients should also be applied daily as a maintenance treatment. When selecting appropriate topical anti-inflammatory treatment for AD flares, several factors should be taken into consideration, including the patient’s age, attitude to treatment options and site of AD lesions. Given the concerns regarding the risk of skin atrophy with use of TCS, a TCI should be used to treat AD lesions in sensitive skin areas: pimecrolimus is recommended for mild-to-moderate AD in these locations, while tacrolimus should be considered for moderate and severe cases. Either pimecrolimus or tacrolimus is recommended for flares in other, non-sensitive body locations. A proactive or intermittent maintenance treatment strategy involving regular emollient use and twice-weekly application of a TCI to previously affected areas is encouraged to reduce the risk of flares.

Conclusions

The algorithm proposed here is intended to simplify the topical treatment of mild-to-moderate AD in daily practice in South and East Asian countries.

Pharmacokinetics and Biodistribution of Tacrolimus after Topical Administration: Implications for Vascularized Composite Allotransplantation

AIM

The high doses of oral tacrolimus (TAC) (1,2) necessary to prevent acute rejection (AR) after vascularized composite allotransplantation (VCA) are associated with systemic adverse effects. The skin is the most antigenic tissue in VCA and the primary target of AR. However, the short-term use of topical TAC (Protopic®), as an off-label adjunct to oral TAC, to treat AR episodes pro re nata (PRN), has yielded inconsistent results. There is lack of data on the pharmacokinetics and tissue distribution of topical TAC in VCA, that hampers our understanding of the reasons for unreliable efficacy. Toward this goal, we evaluated the ability of topical TAC to achieve high local tissue concentrations at the site of application with low systemic concentrations.

MATERIALS AND METHODS

We assessed the pharmacokinetics and tissue distribution of topical TAC (Protopic®, 0.03%) after single or repeated topical application in comparison to those after systemic delivery in rats. Animals received a single topical application of TAC ointment (Group 1) or an intravenous (IV) injection of TAC (Group 2) at a dose of 0.5 mg/kg. In another experiment, animals received daily topical application of TAC ointment (Group 3), or daily intraperitoneal (IP) injection of TAC (Group 4) at a dose of 0.5 mg/kg for 7 days. TAC concentrations in blood and tissues were analyzed by Liquid Chromatography-Mass Spectrometry (LC/MS-MS).

RESULTS

Following single topical administration, TAC was absorbed slowly with a Tmax of 4 h and an absolute bioavailability of 11%. The concentrations of TAC in skin and muscle were several folds higher than whole blood concentrations. Systemic levels remained subtherapeutic (< 3 ng/ml) with repeated once daily applications.

CONCLUSION

Topical application of TAC ointment (Protopic®, 0.03%) at a dose of 0.5 mg/kg/day provided high concentrations in the local tissues with low systemic exposure. Repeated topical administration of TAC is well tolerated with no local or systemic adverse effects. This study confirms the feasibility of topical application of TAC for site specific graft immunosuppression and enables future applications in VCA.

Dermal Delivery of the High-Molecular-Weight Drug Tacrolimus by Means of Polyglycerol-Based Nanogels

Polyglycerol-based thermoresponsive nanogels (tNGs) have been shown to have excellent skin hydration properties and to be valuable delivery systems for sustained release of drugs into skin. In this study, we compared the skin penetration of tacrolimus formulated in tNGs with a commercial 0.1% tacrolimus ointment. The penetration of the drug was investigated in ex vivo abdominal and breast skin, while different methods for skin barrier disruption were investigated to improve skin permeability or simulate inflammatory conditions with compromised skin barrier. The amount of penetrated tacrolimus was measured in skin extracts by liquid chromatography tandem-mass spectrometry (LC-MS/MS), whereas the inflammatory markers IL-6 and IL-8 were detected by enzyme-linked immunosorbent assay (ELISA). Higher amounts of tacrolimus penetrated in breast as compared to abdominal skin or in barrier-disrupted as compared to intact skin, confirming that the stratum corneum is the main barrier for tacrolimus skin penetration. The anti-proliferative effect of the penetrated drug was measured in skin tissue/Jurkat cells co-cultures. Interestingly, tNGs exhibited similar anti-proliferative effects as the 0.1% tacrolimus ointment. We conclude that polyglycerol-based nanogels represent an interesting alternative to paraffin-based formulations for the treatment of inflammatory skin conditions.

Effect of Physiological Changes in the Skin on Systemic Absorption of Tacrolimus Following Topical Application in Rats

Tacrolimus (TL) ointment is a topical treatment for atopic dermatitis, a disease that exhibits various skin conditions. The effect of skin pathologies on the systemic absorption of TL and related side effects remains unknown. This study aimed to investigate factors affecting the cutaneous absorption of TL. We prepared various skin models in hairless rats by tape stripping, injection of prophlogistic material solution (PMS), and continuous subcutaneous adrenaline (Adr) infusion. In vivo absorption studies were conducted, with measurements of transepidermal water loss (TEWL) and skin blood flow as physiological parameters. Very little TL absorption was observed through intact skin. Greater TL absorption was noted in skins with high TEWL values and fully stripped skin with PMS injections. In contrast, Adr infusion, which reduced skin blood flow, resulted in decreased TL absorption through fully stripped skin. Combined use of TL and Adr on skin with PMS injections resulted in suppression of TL absorption. Our results revealed that TL absorption following topical application is affected by alterations in the skin barrier, blood flow, and vascular permeability. We propose an administration plan for TL in a flowchart as a means of preventing systemic side effects.

Developmental Neurotoxic Effects of Percutaneous Drug Delivery: Behavior and Neurochemical Studies in C57BL/6 Mice

Dermatosis often as a chronic disease requires effective long-term treatment; a comprehensive evaluation of mental health of dermatology drug does not receive enough attention. An interaction between dermatology and psychiatry has been increasingly described. Substantial evidence has accumulated that psychological stress can be associated with pigmentation, endocrine and immune systems in skin to create the optimal responses against pathogens and other physicochemical stressors to maintain or restore internal homeostasis. Additionally, given the common ectodermal origin shared by the brain and skin, we are interested in assessing how disruption of skin systems (pigmentary, endocrine and immune systems) may play a key role in brain functions. Thus, we selected three drugs (hydroquinone, isotretinoin, tacrolimus) with percutaneous excessive delivery to respectively intervene in these systems and then evaluate the potential neurotoxic effects. Firstly, C57BL/6 mice were administrated a dermal dose of hydroquinone cream, isotretinoin gel or tacrolimus ointment (2%, 0.05%, 0.1%, respectively, 5 times of the clinical dose). Behavioral testing was performed and levels of proteins were measured in the hippocampus. It was found that mice treated with isotretinoin or tacrolimus, presented a lower activity in open-field test and obvious depressive-like behavior in tail suspension test. Besides, they damaged cytoarchitecture, reduced the level of 5-HT-5-HT1A/1B system and increased the expression of apoptosis-related proteins in the hippocampus. To enable sensitive monitoring the dose-response characteristics of the consecutive neurobehavioral disorders, mice received gradient concentrations of hydroquinone (2%, 4%, 6%). Subsequently, hydroquinone induced behavioral disorders and hippocampal dysfunction in a dose-dependent response. When doses were high as 6% which was 3 times higher than 2% dose, then 100% of mice exhibited depressive-like behavior. Certainly, 6% hydroquinone exposure elicited the most serious impairment of hippocampal structure and survival. The fact that higher doses of hydroquinone are associated with a greater risk of depression is further indication that hydroquinone is responsible for the development of depression. These above data demonstrated that chronic administration of different dermatology drugs contributed into common mental distress. This surprising discovery of chemical stressors stimulating the hippocampal dysfunction, paves the way for exciting areas of study on the cross-talk between the skin and the brain, as well as is suggesting how to develop effective and safe usage of dermatological drugs in daily practice.

Topical treatments for scalp psoriasis

BACKGROUND

People with chronic plaque psoriasis often have lesions on the scalp. Hair makes the scalp difficult to treat and the adjacent facial skin is particularly sensitive to topical treatments.

OBJECTIVES

To assess the efficacy and safety of topical treatments for scalp psoriasis.

SEARCH METHODS

We searched the following databases up to August 2015: the Cochrane Skin Group Specialised Register, CENTRAL (2015, Issue 7), MEDLINE (from 1946), EMBASE (from 1974) and LILACS (from 1982). We also searched five trials registers, screened abstracts of six psoriasis-specific conferences and checked the reference lists of included studies for further references to relevant randomised controlled trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with a parallel-group, cross-over or within-patient design of topical treatments for people of all ages with scalp psoriasis.

DATA COLLECTION AND ANALYSIS

Two authors independently carried out study selection, data extraction and 'Risk of bias' assessment. Disagreements were settled by reference to a third author.To assess the quality of evidence, we focused on the following outcomes: 'clearance' or 'response' as assessed by the investigator global assessment (IGA), improvement in quality of life, adverse events requiring withdrawal of treatment and 'response' as assessed by the patient global assessment (PGA).We expressed the results of the single studies as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes, and mean differences (MD) with 95% CI for continuous outcomes. If studies were sufficiently homogeneous, we meta-analysed the data by using the random-effects model. Where it was not possible to calculate a point estimate for a single study, we described the data qualitatively. We also presented the number needed to treat to benefit (NNTB).We categorised topical corticosteroids according to the German classification of corticosteroid potency as mild, moderate, high and very high.

MAIN RESULTS

We included 59 RCTs with a total of 11,561 participants. Thirty studies were either conducted or sponsored by the manufacturer of the study medication. The risk of bias varied considerably among the included studies. For instance, most authors did not state the randomisation method and few addressed allocation concealment. Most findings were limited to short-term treatments, since most studies were conducted for less than six months. Only one trial investigated long-term therapy (12 months). Although we found a wide variety of different interventions, we limited the grading of the quality of evidence to three major comparisons: steroid versus vitamin D, two-compound combination of steroid and vitamin D versus steroid monotherapy and versus vitamin D.In terms of clearance, as assessed by the IGA, steroids were better than vitamin D (RR 1.82; 95% CI 1.52 to 2.18; four studies, 2180 participants, NNTB = 8; 95% CI 7 to 11; moderate quality evidence). Statistically, the two-compound combination was superior to steroid monotherapy, however the additional benefit was small (RR 1.22; 95% CI 1.08 to 1.36; four studies, 2474 participants, NNTB = 17; 95% CI 11 to 41; moderate quality evidence). The two-compound combination was more effective than vitamin D alone (RR 2.28; 95% CI 1.87 to 2.78; four studies, 2008 participants, NNTB = 6; 95% CI 5 to 7; high quality evidence).In terms of treatment response, as assessed by the IGA, corticosteroids were more effective than vitamin D (RR 2.09; 95% CI 1.80 to 2.41; three studies, 1827 participants; NNTB = 4; 95% CI 4 to 5; high quality evidence). The two-compound combination was better than steroid monotherapy, but the additional benefit was small (RR 1.15; 95% CI 1.06 to 1.25; three studies, 2444 participants, NNTB = 13; 95% CI 9 to 24; moderate quality evidence). It was also more effective than vitamin D alone (RR 2.31; 95% CI 1.75 to 3.04; four studies, 2222 participants, NNTB = 3; 95% CI 3 to 4; moderate quality evidence).Reporting of quality of life data was poor and data were insufficient to be included for meta-analysis.Steroids caused fewer withdrawals due to adverse events than vitamin D (RR 0.22; 95% CI 0.11 to 0.42; four studies, 2291 participants; moderate quality evidence). The two-compound combination and steroid monotherapy did not differ in the number of adverse events leading withdrawal (RR 0.88; 95% CI 0.42 to 1.88; three studies, 2433 participants; moderate quality evidence). The two-compound combination led to fewer withdrawals due to adverse events than vitamin D (RR 0.19; 95% CI 0.11 to 0.36; three studies, 1970 participants; high quality evidence). No study reported the type of adverse event requiring withdrawal.In terms of treatment response, as assessed by the PGA, steroids were more effective than vitamin D (RR 1.48; 95% CI 1.28 to 1.72; three studies, 1827 participants; NNTB = 5; 95% CI 5 to 7; moderate quality evidence). Statistically, the two-compound combination was better than steroid monotherapy, however the benefit was not clinically important (RR 1.13; 95% CI 1.06 to 1.20; two studies, 2226 participants; NNTB = 13; 95% CI 9 to 26; high quality evidence). The two-compound combination was more effective than vitamin D (RR 1.76; 95% CI 1.46 to 2.12; four studies, 2222 participants; NNTB = 4; 95% CI 3 to 6; moderate quality evidence).Common adverse events with these three interventions were local irritation, skin pain and folliculitis. Systemic adverse events were rare and probably not drug-related.In addition to the results of the major three comparisons we found that the two-compound combination, steroids and vitamin D monotherapy were more effective than the vehicle. Steroids of moderate, high and very high potency tended to be similarly effective and well tolerated. There are inherent limitations in this review concerning the evaluation of salicylic acid, tar, dithranol or other topical treatments.

AUTHORS' CONCLUSIONS

The two-compound combination as well as corticosteroid monotherapy were more effective and safer than vitamin D monotherapy. Given the similar safety profile and only slim benefit of the two-compound combination over the steroid alone, monotherapy with generic topical steroids may be fully acceptable for short-term therapy.Future RCTs should investigate how specific therapies improve the participants' quality of life. Long-term assessments are needed (i.e. 6 to 12 months).

[Efficiency of tacrolimus therapy for perianal Crohn's disease]

AIM

To determine the efficacy of 0.1% tacrolimus ointment in patients with perianal Crohn's disease (CD).

SUBJECTS AND METHODS

This prospective randomized trial enrolled 20 patients with perianal CD as anal fissures and rectal fistulas. The inclusion criteria were rectovaginal or extrasphincteric fistulas and purulent leakages. A study group comprised 11 patients, including 9 with anal fissures and 2 with fistulas. A control group included 9 patients, including 8 with fissures and 1 with fistulas. The study group received systemic therapy with azathioprine 2 mg/kg/day and tacrolimus ointment 2 mg/day; the control group had systemic therapy with azathioprine 2 mg/kg/day, hormone ointment 1 mg/day, and metronidazole suppositories 250 mg/day. Control examination and perianal CD activity index (PCDAI) determination were done 6 and 12 weeks after therapy initiation.

RESULTS

At 6 weeks after beginning the study, local examination revealed the signs of anal fissure epithelialization in 5 (45.5%) of the 11 patients in the study group and in 3 (33.3%) of the 9 patients in the control one. At 12 weeks, fissure epithelialization and fistula obliteration were stated in 6 (54%) patients in the study group and in 3 (33%) of the 9 patients in the control group. At 12 weeks, PCDAI in the study and control groups was 2.00 and 4.44 scores (p = 0.01).

CONCLUSION

The findings suggest that topical 0.1% tacrolimus ointment versus antibacterial suppositories and hormone ointments is effective in treating patients with perianal CD. Topical 0.1% tacrolimus ointment therapy caused a reduction in PCDAI.

Successful treatment of localized pemphigus foliaceus with topical pimecrolimus

We report the case of successful treatment of a 79-year-old male patient with recurrent pemphigus foliaceus with pimecrolimus cream 1% once daily for 40 days. The patient initially presented with localized lesions on the scalp and nose area and was treated with systemic corticosteroids. At his fourth relapse within a period of 16 months, he refused any systemic treatment. Pimecrolimus cream was suggested to him as an alternative option.

Tacrolimus fails to regulate collagen expression in dermal fibroblasts

BACKGROUND

The purpose of this study was to investigate the effects of tacrolimus on human fibroblasts derived from unwounded skin, hypertrophic scars (HTS), and keloids. We hypothesized that tacrolimus, a potent anti-inflammatory and immunosuppressant drug known to attenuate solid organ transplant fibrosis, would block collagen expression in human dermal fibroblasts.

METHODS

We performed genomewide microarray analysis on human dermal fibroblasts treated with tacrolimus in vitro. We used principal component analysis and hierarchical clustering to identify targets regulated by tacrolimus. We performed quantitative polymerase chain reaction to validate the effect of tacrolimus on collagen 1 and 3 expression.

RESULTS

We identified 62, 136, and 185 gene probes on microarray analysis that were significantly regulated (P < 0.05) by tacrolimus in normal, HTS, and keloid fibroblasts, respectively. Collagen pathways were not blocked after tacrolimus exposure in any of the fibroblast groups; we validated these findings using quantitative polymerase chain reaction for collagen 1 and 3. Microarray gene expression of NME/NM23 nucleoside diphosphate kinase 1 and heterogeneous nuclear ribonucleoprotein H3-2H9 were significantly downregulated (P < 0.05) by tacrolimus in both HTS and keloid fibroblast populations but not normal fibroblasts.

CONCLUSIONS

Tacrolimus does not modulate the expression of collagen 1 or 3 in human dermal fibroblasts in vitro. Microarray gene expression of NME/NM23 nucleoside diphosphate kinase 1 and heterogeneous nuclear ribonucleoprotein H3-2H9 are blocked by tacrolimus in pathologic fibroblasts but not normal fibroblasts, and may represent novel genes underlying HTS and keloid pathogenesis. Tacrolimus-based anti-fibrotics might prove more effective if non-fibroblast populations such as inflammatory cells and keratinocytes are targeted.

Site-specific immunosuppression in vascularized composite allotransplantation: prospects and potential

Skin is the most immunogenic component of a vascularized composite allograft (VCA) and is the primary trigger and target of rejection. The skin is directly accessible for visual monitoring of acute rejection (AR) and for directed biopsy, timely therapeutic intervention, and management of AR. Logically, antirejection drugs, biologics, or other agents delivered locally to the VCA may reduce the need for systemic immunosuppression with its adverse effects. Topical FK 506 (tacrolimus) and steroids have been used in clinical VCA as an adjunct to systemic therapy with unclear beneficial effects. However, there are no commercially available topical formulations for other widely used systemic immunosuppressive drugs such as mycophenolic acid, sirolimus, and everolimus. Investigating the site-specific therapeutic effects and efficacy of systemically active agents may enable optimizing the dosing, frequency, and duration of overall immunosuppression in VCA with minimization or elimination of long-term drug-related toxicity.

Calcineurin inhibitors in pediatric atopic dermatitis: a review of current evidence

Atopic dermatitis (AD) is a common, chronic inflammatory dermatosis with a prevalence of 7-21% in school-aged children. Childhood AD has a profound impact on the social, personal, emotional, and financial perspectives of families. For the last half-century, topical corticosteroids of different potencies have been the mainstay of topical therapy. In recent years, two topical calcineurin inhibitors (TCIs), tacrolimus and pimecrolimus, have become available for the treatment of AD. Both tacrolimus and pimecrolimus have been extensively evaluated in the management of pediatric AD. Trials comparing them with placebo, topical corticosteroids, and each other have shown them to be effective and safe for continuous short-term use, and for noncontinuous use for up to 4 years. Long-term safety of TCIs is not known as they have been in clinical use for less than a decade.

Tacrolimus: 10 years of successful clinical application

Tacrolimus (FK506) is the first drug from the new class of drugs - calcineurin inhibitors. It has a great potential and can change the current approaches to treatment of different dermatoses. Topical forms of Tacrolimus are activated due to the effect on T-lymphocyte signal transduction, and they also inhibit gene transcription. As a result, the T-cell response to antigens is alleviated. Percutaneous absorption of Tacrolimus in affection foci is higher than in healthy skin. Due to this a smaller amount of the drug is absorbed by the skin as long as the skin is healed. Systemic absorption of Tacrolimus is low in the course of treatment. The maximum clinical experience has been gained in the field of applying Tacrolimus for treatment of atopic dermatitis. In a number of clinical studies, 0.03-0.3% Tacrolimus ointment efficiently reduced the severity of symptoms and course of atopic dermatitis in adults and children. Moreover, topical treatment with Tacrolimus did not involve any substantial toxic effects. The patients most often complained of local irritations in the area where the ointment was applied, which were transient by nature and did not demand the drug withdrawal. Today Tacrolimus is a valuable and safer alternative to glucocorticosteroids for treatment of atopic dermatitis. It can also be used for treating other dermatoses, which demands additional all-round examination.

Role of topical calcineurin inhibitors in the treatment of seborrheic dermatitis: a review of pathophysiology, safety, and efficacy

Seborrheic dermatitis (SD) is characterized by erythematous pruritic patches and plaques with greasy scale that occur in sebaceous areas. It is common, affecting up to 3% of the population. Past treatments have relied on a wide variety of anti-inflammatory and antifungal agents, but corticosteroids have limited use because of long-term adverse effects. Topical calcineurin inhibitors provide a safe alternative for the treatment of SD, as these drugs block the inflammatory cascade involved in the disease process and pose no risk of skin atrophy. Studies of topical pimecrolimus and tacrolimus in the treatment of SD have found that improvement occurred within 2 weeks, and if SD recurred after stopping treatment, it was significantly less severe. There have been no studies of the comparative efficacy of pimecrolimus versus tacrolimus for the treatment of SD. Common adverse effects of mild burning and irritation have been associated with the use of both of these agents. Safety profile studies are limited to studies of atopic dermatitis, which show no increase in infection rate, photocarcinogenicity, or signs of immunosuppression in patients using topical calcineurin inhibitors for long-term treatment. This article reviews the clinical trials of pimecrolimus and tacrolimus in the treatment of SD, focusing on efficacy and safety.

Daily topical tacrolimus therapy prevents skin rejection in a rodent hind limb allograft model

BACKGROUND

Skin is the most immunogenic component of a composite tissue allograft. Topical immunotherapy is an attractive therapeutic modality with which to provide local immunosuppression, with minimal systemic toxicity. The present study was performed to investigate the potential of topical tacrolimus to prolong survival of the skin component of a composite tissue allograft.

METHODS

Wistar Furth-to-Lewis rat orthotopic hind limb transplants were performed. Group I consisted of rats treated with topical tacrolimus; group II, antilymphocyte serum plus 21 days cyclosporine; and group III, antilymphocyte serum plus 21 days of cyclosporine plus topical tacrolimus. In group IV, tacrolimus levels in blood, skin, and muscle were measured in an autograft control group.

RESULTS

All animals in group I (n = 8) developed grade III clinical rejection by postoperative day 9. In group II (n = 9), the median onset of grade III rejection was postoperative day 40 (range, postoperative days 34 to 44). In group III (n = 6), two animals developed focal grade III rejection on postoperative days 35 and 56. The remaining four animals reached the 100-day endpoint without grade III rejection. In group IV, tacrolimus levels were low or undetectable in blood, whereas skin levels were 100-fold higher than underlying muscle.

CONCLUSIONS

Topical tacrolimus therapy has the potential to prevent skin rejection in a composite tissue allograft. Preoperative depletion of T cells with antilymphocyte serum, along with a short course of systemic immunosuppression, prevents acute rejection, whereas topical tacrolimus inhibits immune cell function in the skin. Concentrations of tacrolimus are substantially higher in skin compared with underlying muscle and peripheral blood. Topical immunotherapy could reduce the morbidity associated with systemic immunosuppression in clinical composite tissue allografts.

Topical application of sphingosine-1-phosphate and FTY720 attenuate allergic contact dermatitis reaction through inhibition of dendritic cell migration

Migration of Langerhans cells (LCs) from the skin to the lymph node is an essential step in the pathogenesis of allergic contact dermatitis (ACD). Therefore, inhibition of LC-migration could be a promising strategy to improve this skin disease. Effects of sphingosine-1-phosphate (S1P) and the immunomodulator FTY720 on LC trafficking is not well defined, yet. Thus, we investigated the action of topically administered S1P and FTY720 in a murine model of ACD. Most interestingly, FTY720 as well as S1P inhibited the inflammatory reaction in the elicitation phase of ACD. In the sensitization phase, FTY720, and S1P reduced the weight and cell count of the draining auricular lymph node, as well as immigrated dendritic cells provoked by repetitive topical administration of the hapten. Correspondingly, the density of LCs in the epidermis was higher in FTY720- and S1P-treated mice compared to vehicle treatment. A skin dendritic cell migration assay confirmed the significant inhibition of dendritic cell migration by FTY720 and S1P. These data supply conclusive evidence that the strategy of targeting the migratory response of LCs with locally acting S1P or FTY720 represents an emerging option in the treatment of allergic skin diseases like contact hypersensitivity and atopic dermatitis.

New insights into the mechanism and management of allergic diseases: atopic dermatitis

Rapidly increasing knowledge on the complex background of atopic dermatitis (AD) on the genetic, immunological and environmental level in combination with the continuous improvement in our diagnostic options has initiated an ongoing discussion on factors, which primarily promote the disease on one hand and mechanisms which emerge rather secondarily as a consequence of disease-specific modifications, on the other hand. Beside a sustained search for reliable and meaningful diagnostic tools for elicitors of the disease, novel therapeutic approaches are required, as most of the treatments of AD are limited to symptomatic therapies. In contrast, therapeutic approaches selectively regulating aberrant pathophysiological mechanisms in AD itself would be much more effective and promising.

The bark of Betula platyphylla var. japonica inhibits the development of atopic dermatitis-like skin lesions in NC/Nga mice

The bark of Betula platyphylla Sukat. var. japonica Hara (Asian White Birch, AWB) is one of the herbs used in Eastern countries for the treatment of various inflammatory diseases including atopic dermatitis (AD). The present study was performed to examine if and how the bark of AWB inhibits the development of AD-like skin lesions in NC/Nga mice induced by repeated application of picryl chloride (PC). With this aim, we examined the skin symptom severity, itching behavior, serum immunoglobulin (Ig) E level and mRNA expression of cytokines at iliac and cervical lymph nodes in the mice. Oral administration of AWB extracts (25, 100 and 250 mg/kg) to the PC-treated mice inhibited the development of AD-like skin lesions as exemplified by a significant decrease in the total skin severity scores, itching behavior and a decrease in hypertrophy and infiltration of inflammatory cells into dermis. The serum IgE level was also significantly reduced by AWB extract. In the RT-PCR results, the expression of interleukin-4 mRNA was reduced by AWB extract, whereas the expression of interferon-gamma mRNA was not changed. These results suggest that AWB inhibits the development of AD-like skin lesions in NC/Nga mice through the suppression of the T-helper 2 cell response.

Langerhans Cell Receptors

Langerhans cells (LC) are a subtype of dendritic cells, which reside in the epidermis. LCs are antigen-presenting cells that originate in bone marrow and enter the epidermis through blood vessels. LCs exhibit a variety of antigen receptors that are able to respond to a wide range of antigens. Within the last two decades, these receptors have been the subject of considerable research. This article focuses on the rapidly growing body of knowledge with respect to the functions of LC receptors.

[The future of immunotherapy for composite tissues allotransplantation]

Hand and composite tissue allotransplantation (CTA) holds great potential for reconstructive surgery but its development is currently limited by the side effects of the immunosuppressive drugs. Induction of specific tolerance, a situation where the recipient does not mount an immune response against the allograft but remains fully immunocompetent, holds exciting promise. Generation of mixed hematopoietic chimerism by infusing the recipient with donor bone marrow cells has been shown to induce tolerance without chronic immunosuppression. Genetic matching of the donor and the recipient is another option for transplanting composite tissues with only an initial course of immunosuppression. Experiments demonstrated long-term survival of musculoskeletal allografts between MHC-matched miniature swine. Finally, new immunosuppressive agents with a more targeted action will reduce side effects and may prevent the development of chronic rejection. Skin-specific immunosuppression is particularly useful for limb transplants since skin, regarded as the most antigenic component, is easily accessible to topical or irradiation therapies.

Comparison of the efficacy and safety of 0.1% tacrolimus ointment with topical corticosteroids in adult patients with atopic dermatitis: review of randomised, double-blind clinical studies conducted in Japan

Tacrolimus (FK506) ointment is widely used in the treatment of patients with atopic dermatitis. The drug exerts its action by down-regulating antigen-specific T-cell activities and associated proinflammatory cytokine production. A number of clinical studies have evaluated the efficacy and safety of 0.1% tacrolimus ointment compared with vehicle or topical corticosteroids in adult patients with atopic dermatitis. These studies have suggested that topical tacrolimus has a rapid onset of action and exerts sustained therapeutic effects, with an efficacy similar to that of moderate to potent topical corticosteroids, but without causing skin atrophy. Two phase III randomised, controlled clinical trials have been conducted in Japanese adult patients with atopic dermatitis to compare the efficacy and safety of topical 0.1% tacrolimus with topical corticosteroid ointments. In the first study, patients with moderate or severe atopic dermatitis on the trunk and extremities were randomised to 3 weeks of treatment with topical 0.1% tacrolimus or the mid-potency topical corticosteroid 0.12% betamethasone valerate. Over 90% of the patients in each study group experienced at least a moderate improvement at the end of the study. In the second study, patients with moderate or severe atopic dermatitis on the head or neck were randomised to 1 week of treatment with 0.1% tacrolimus or the mild-potency corticosteroid 0.1% alclometasone dipropionate. Significantly greater improvements in individual symptom scores were observed with topical tacrolimus compared with alclometasone dipropionate, with overall global improvement at 1 week being statistically superior with tacrolimus. Furthermore, in a long-term open-label study involving 568 patients, at least a moderate global improvement in symptoms was observed in 85% of patients at 6 weeks, increasing to 91% at both 26 weeks and 52 weeks; this rate was maintained throughout the 2-year duration of the study. 0.1% tacrolimus ointment was considered to be safe in the majority of patients. The most prevalent adverse reactions were local application site irritations, which generally resolved with continued therapy. In summary, these findings suggest that 0.1% tacrolimus ointment is an effective and safe nonsteroidal alternative therapy for adult patients with atopic dermatitis.

Netherton syndrome: Successful use of topical tacrolimus and pimecrolimus in four siblings

Netherton's syndrome (NS) is a rare autosomal recessive disease comprised of ichthyosis in the form of ichthyosis linearis circumflexa, hair shaft defects and atopic manifestations with an elevated IgE level. Various therapeutic options have been used in NS with variable success. Tacrolimus and pimecrolimus belong to the family of calcineurin inhibitors. They bind cytoplasmic proteins and the resulting complex binds calcineurin, inhibiting its ability to dephosphorylate the nuclear factor of activated T cells, thus suppressing gene transcription. There have been conflicting reports of the usefulness of tacrolimus in NS patients, with systemic absorption being the main adverse outcome. Here we report four Saudi siblings (two boys and two girls) with NS who were treated with topical tacrolimus and pimecrolimus with good control of their skin disease without any toxic effect. To our knowledge, this is the second report of the use of topical pimecrolimus in NS in the English literature.

A Double-Blind Randomized Placebo-Controlled Pilot Study Comparing Topical Immunomodulating Agents and Corticosteroids for Treatment of Experimentally Induced Nickel Contact Dermatitis

BACKGROUND

Although topical glucocorticoids are effective for most inflammatory skin disorders, their use is limited by local and systemic side effects. Tacrolimus and pimecrolimus are immunomodulators that provide clinicians with steroid-sparing options in the long-term topical treatment of allergic contact dermatitis.

OBJECTIVE

To obtain pilot data regarding the relative efficacies of pimecrolimus 1% cream, tacrolimus 0.1% ointment, clobetasol propionate 0.05% ointment, and triamcinolone acetonide 0.1% ointment, as compared to control preparations (Vanicream and petrolatum), for treatment of experimentally induced nickel contact dermatitis.

METHODS

Twenty-one volunteers with positive patch test reactions to nickel sulfate 5% at six sites (three on each arm) applied each study medication to one nickel site, respectively, twice daily for 14 days. Study medications were prepared in identical syringes, and the site of application was randomly assigned by a computer-generated randomization schedule. Assessments were performed at 3, 7, 10, and 14 days after randomization.

RESULTS

Most reactions were coded as resolved or as almost resolved by day 14 regardless of treatment. Although most pairwise comparisons were not statistically significant, a clear trend was observed for sites treated with active drug to do better than control sites.

CONCLUSION

Possible explanations for these results include contamination by neighboring medication sites, timing of assessments, and lack of repeated nickel applications.

Cancer concerns with topical immunomodulators in atopic dermatitis: overview of data and recommendations to clinicians

The topical immunomodulators tacrolimus and pimecrolimus were approved for the treatment of atopic dermatitis in 2000 and 2001, respectively. However, on 20 January 2006, the US FDA approved a 'black box' warning for these agents because of concerns regarding a possible link to development of malignancy. These concerns were based upon the known mechanism of action of this drug class, the results of animal studies, and case reports. This article provides an overview of the data that led to the approval by the FDA of a 'black box' warning and concludes that physicians, patients, and caregivers should feel confident about using tacrolimus and pimecrolimus for atopic dermatitis so long as they follow the FDA guidelines.

Atopic eczema: what's new?

Atopic eczema (AE) is a chronic inflammatory skin disease characterized by recurrent intense pruritus and a typical age-related distribution of skin lesions. Several new aspects with regard to the pathogenetic background as well as strategies for prevention, diagnosis and treatment of AE have emerged. There are ongoing studies on genetic susceptibility loci, as well as environmental and nutritional factors associated with an increase or a decrease of AE lesions. The atopy patch test is now available for identification of allergens in aeroallergen-triggered AE. New topical therapies, such as the calcineurin inhibitors, have broadened the therapeutic armamentarium substantially. In order to increase knowledge and coping strategies, patient education programs have been launched. Learning objective Upon completing this paper, the reader should be aware of new developments in AE, especially on nomenclature, prevention strategies, diagnostic tests, as well as therapeutic options.

Comparison of topical tacrolimus 0.1 % in pectin ointment with clobetasol 0.5% ointment in adults with moderate to severe desquamative gingivitis: A 4-week, randomized, double-blind clinical trial

BACKGROUND

Desquamative gingivitis (DG) is a clinical condition characterized by red, painful, glazed, and friable gingiva, which might be a manifestation of some autoimmune mucocutaneous diseases. The time from the development of initial signs of DG to diagnosis can vary from months to years. Based on a literature search, no data concerning patients with DG without signs of autoimmune disease were available.

OBJECTIVE

The aim of this trial was to compare the efficacy and tolerability of monotherapy with topical tacrolimus 0.1% in pectin ointment versus clobetasol propionate 0.5% ointment in adults affected by DG.

METHODS

This randomized, double-blind clinical trial was conducted at the Dipartimento di Medicina Clinica e Sperimentale, Universita di Verona, Verona, Italy. Patients aged > or =18 years were selected using the department's electronic medical records based on a clinical diagnosis of moderate to severe DG. After a 2-week washout period, patients were randomly assigned to receive 2 mL of tacrolimus 0.1% in pectin (equivalent to 0.2 mg of tacrolimus) or 2 mL of clobetasol propionate 0.5% ointment (equivalent to 1 mg of clobetasol) QD for 4 weeks. Evaluations were performed before treatment (baseline), after the treatment period (week 4), and at 2 follow-up visits at weeks 6 and 8. The signs of DG (ie, erythema [atrophy] and desquamation [erosions/ulceration]) were quantified by a blinded investigator using a calculated score based on their surface extension, using a drawing in which the areas of various zones of the mouth were indicated as a percentage of the whole oral mucosa. Severity of erythema and desquamation was rated on a 4-point scale (0 = absent; 1 = involvement of <5% of surface [mild]; 2 = 5%-15% [moderate]; and 3 = >15% [severe]). The primary end point was the number of patients who achieved remission (severity score of 0) in either sign; the secondary end point was the proportions of patients achieving improvement (severity score of 0 or 1) in either sign. Before and after treatment, we measured the serum concentrations of tacrolimus and its metabolites with an immunoenzymatic assay kit. Tolerability was assessed using hematology, biochemistry, urinalysis, measurements of systolic/diastolic blood pressure and heart rate, patient interview, and spontaneous reporting.

RESULTS

A total of 24 patients (18 women, 6 men; all white of Italian origin; age range, 21-65 years; 12 patients per treatment group) were enrolled in the study. In the tacrolimus group, 11 (91.7%) patients achieved remission of erythema and/or desquamation at weeks 4 and 6; at week 8, these rates were 9 (75.0%) and 8 (66.7%), respectively; none of the patients in the clobetasol group achieved remission of either sign at any time point (all, P < 0.001). At weeks 4, 6, and 8, significantly greater proportions of patients treated with tacrolimus had improved erythema and desquamation compared with those treated with clobetasol (all, P < 0.001). At week 4, all patients had undetectable serum tacrolimus concentrations (<1.5 microg/L). Six (50.0%) patients in the tacrolimus group reported a mild oral burning sensation, and 6 (50.0%) patients in the clobetasol group reported mild mouth dryness. No other adverse events were reported.

CONCLUSIONS

The results of this small study suggest that topical tacrolimus 0.1 % in pectin was more effective compared with clobetasol propionate 0.5% ointment in the treatment of DG. Both treatments were generally well tolerated in the population studied.

Pimecrolimus and tacrolimus differ in their inhibition of lymphocyte activation during the sensitization phase of contact hypersensitivity

BACKGROUND

As reported previously, oral administration of the calcineurin inhibitors (CNI) pimecrolimus and tacrolimus resulted in equipotent inhibition of the elicitation phase of contact hypersensitivity (CHS) in mice. The sensitization phase was inhibited by tacrolimus but was unaffected by pimecrolimus, even at higher doses.

OBJECTIVE

The kinetics of lymph node hyperplasia and up-regulation of T and B cell activation antigens were analyzed to obtain a better understanding of the divergent CNI profile in CHS.

METHODS

Lymph node (LN) cells of CNI-untreated and treated mice were examined with flow cytometry at various time points after sensitization with oxazolone. LN hyperplasia and drug levels were also determined.

RESULTS

Sensitization induced a higher portion of LN cells expressing the activation antigens CD25, CD69 and CD134 and an increase in activated B cells (B220(+)/CD40(+)) compared to naïve mice. Up-regulation of these markers was completely or profoundly blocked with tacrolimus, whereas pimecrolimus at the three-fold higher dose caused significantly less inhibition. Tacrolimus also completely blocked the sensitization-associated increase of CD11c(+) antigen presenting cells (APC) in LN, whereas pimecrolimus showed significantly less inhibition. In contrast to tacrolimus, LN weight and cellularity were not affected by pimecrolimus at any time point after sensitization. Concentration of tacrolimus in blood and in the draining LN substantially exceeded that of pimecrolimus by factors 6.7-14 and 5.6-5.8, respectively, at the same dose levels.

CONCLUSION

In contrast to tacrolimus, systemic treatment of mice with pimecrolimus only weakly interferes with lymphocyte activation and does not affect hyperplasia of the draining lymph nodes during sensitization.

Eyeglass frame allergic contact dermatitis: does tacrolimus prevent recurrences?

A 35-year-old man developed well-demarcated, oedematous and erosive erythematous lesions on the nasal bridge and retroauricular regions bilaterally. His eyeglass frame was repaired by an optician 2 weeks prior to symptom onset. Patch testing revealed a positive reaction to scrapings of nose pads and temples of the frame in petrolatum. Because the patient did not take our exhortation to change eyeglass frames, we advised him to cover their nose pads and temples with vinyl tape to prevent direct skin contact. Although topical corticosteroid therapy produced clinical resolution temporally, recurrences were not prevented. After starting tacrolimus ointment therapy, recurrence has not occurred for 9 months. Tacrolimus may be effective for allergic contact dermatitis patients who cannot avoid repeated allergen exposure, as it may not only reduce inflammation but inhibit recurrences.

Les voies de recherche en immunologie appliquées à l'allotransplantation de tissus composites

Hand and composite tissue allotransplantation (CTA) holds great potential for reconstructive surgery but its development is currently limited by the side-effects of the immunosuppressive drugs. Induction of specific tolerance, a situation where the recipient does not mount an immune response against the allograft but remains fully immunocompetent, holds exciting promise. Generation of mixed hematopoietic chimerism by infusing the recipient with donor bone marrow cells has been shown to induce tolerance without chronic immunosuppression. Genetic matching of the donor and the recipient is another option for transplanting composite tissues with only an initial course of immunosuppression. Experiments demonstrated long-term survival of musculoskeletal allografts between MHC-matched miniature swine. Finally, new immunosuppressive agents with a more targeted action will reduce side-effects and may prevent the development of chronic rejection. Skin-specific immunosuppression is particularly useful for limb transplants since skin, regarded as the most antigenic component, is easily accessible to topical or irradiation therapies.

Pharmacological targeting of catalyzed protein folding: the example of peptide bond cis/trans isomerases

Peptide bond isomerases are involved in important physiological processes that can be targeted in order to treat neurodegenerative disease, cancer, diseases of the immune system, allergies, and many others. The folding helper enzyme class of Peptidyl-Prolyl-cis/trans Isomerases (PPIases) contains the three enzyme families of cyclophilins (Cyps), FK506 binding proteins (FKBPs), and parvulins (Pars). Although they are structurally unrelated, all PPIases catalyze the cis/trans isomerization of the peptide bond preceding the proline in a polypeptide chain. This process not only plays an important role in de novo protein folding, but also in isomerization of native proteins. The native state isomerization plays a role in physiological processes by influencing receptor ligand recognition or isomer-specific enzyme reaction or by regulating protein function by catalyzing the switch between native isomers differing in their activity, e.g., ion channel regulation. Therefore elucidating PPIase involvement in physiological processes and development of specific inhibitors will be a suitable attempt to design therapies for fatal and deadly diseases.

The role of dendritic cell subtypes in the pathophysiology of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is an inflammatory, immunologically mediated skin disease characterized by a T helper type 2 cell-predominant phenotype initially with additional acquisition of T helper type 1 cell phenotype during the chronic eczematous phase. Compelling evidence presented here suggests that two types of dendritic cells (DC), myeloid DC (mDC) and plasmacytoid DC (pDC), are important in the pathogenesis of AD.

METHODS

We reviewed the current literature and summarized key information about the role of mDC and pDC in the pathogenesis of AD.

RESULTS

Langerhans cells and inflammatory dendritic epidermal cells, which bear the high-affinity receptor for immunoglobulin E on their cell surface, are hypothesized to contribute to the pathogenesis of AD. pDC, Which play an important role in the defence against viral infections, have also been shown to express high-affinity receptor for immunoglobulin E.

CONCLUSION

Immunoglobulin E receptor-bearing mDC and pDC subtypes in the blood and the skin of patients with AD are of critical immunologic importance in the complex pathophysiologic network of AD. Targeting mDC and pDC subtypes may lead to effective new therapies for the management of AD.

Atopic dermatitis: beyond the itch that rashes

The prevalence of atopic dermatitis is increasing, and more than 50% of children with atopic dermatitis go on to develop asthma and allergies. A better understanding of the underlying immune abnormalities of this complex chronic relapsing skin disease is needed. Although the optimal treatment approach remains to be defined, several recent studies suggest a rationale for using topical calcineurin inhibitors as early intervention and adding topical corticosteroids as rescue therapy if needed.

Safety and efficacy of topical calcineurin inhibitors in the treatment of childhood atopic dermatitis

Approximately 10-20% of infants in industrialized countries experience atopic dermatitis. In recent decades topical corticosteroids have been the first-choice therapy for treatment of flares. However, this form of therapy may induce skin atrophy, especially after application to facial lesions or with long-term use. Thus, development of new anti-inflammatory topical agents for the treatment of childhood atopic dermatitis was needed. The topical calcineurin inhibitors tacrolimus and pimecrolimus have an effect on various cells of the cutaneous immune system, specifically on T cells, by inhibiting the phosphatase calcineurin and preventing the transcription of proinflammatory cytokines. In several clinical studies of children and adults with atopic dermatitis, topical calcineurin inhibitors were found to be effective both on the face and the trunk and extremities, in both short- and long-term treatment regimens. Tachyphylaxis or rebound were not observed. In most patients an improvement of their eczema occurred during the first week of treatment, as measured by subjective and objective clinical signs of atopic dermatitis. Treatment significantly reduced the incidence of flares and the need for corticosteroids in children and adults. Treatment success, commonly defined as 'excellent improvement' or 'clearing of all lesions', was observed in more than one-third of all children treated with 0.03% or 0.1% tacrolimus or 1% pimecrolimus. Topical application of pimecrolimus and tacrolimus does not lead to significant blood concentrations of these agents in the majority of children with atopic dermatitis, and any increase in blood concentrations decreases after a few days of therapy. No changes in laboratory parameters were observed in short- and long-term studies in patients with atopic dermatitis. The most common adverse effect following the application of topical calcineurin inhibitors is mild to moderate symptoms of irritation such as burning, erythema and pruritus, which occurred in up to 20% of all children treated with tacrolimus and 10% of children treated with pimecrolimus, and usually faded after a few days. In contrast to topical corticosteroids, calcineurin inhibitors do not induce skin atrophy, even after long-term use. Topical calcineurin inhibitors have been proven to be effective and have a good safety profile during short-term and long-term use for up to 1 year with pimecrolimus and up to 4 years with tacrolimus. Given the lack of extensive experience with use of topical calcineurin inhibitors over longer periods, regular use of these agents, particularly in children, should be undertaken only after careful consideration of individual cases. Sun protection should also be advised.

Pimecrolimus in dermatology: atopic dermatitis and beyond

Pimecrolimus is a calcineurin inhibitor developed for the topical therapy of inflammatory skin diseases, particularly atopic dermatitis (AD). Pimecrolimus selectively targets T cells and mast cells. Pimecrolimus inhibits T-cell proliferation, as well as production and release of interleukin-2 (IL-2), IL-4, interferon-gamma and tumour necrosis factor-alpha. Moreover, pimecrolimus inhibits mast cell degranulation. In contrast to tacrolimus, pimecrolimus has no effects on the differentiation, maturation and functions of dendritic cells. In contrast to corticosteroids, pimecrolimus does not affect endothelial cells and fibroblasts and does not induce skin atrophy. Given the low capacity of pimecrolimus to permeate through the skin, it has a very low risk of systemic exposure and subsequent systemic side-effects. In different randomised controlled trials, topical pimecrolimus as cream 1% (Elidel) has been shown to be effective, well tolerated and safe in both adults and children with mild to moderate AD. In addition, pimecrolimus has been successfully used in inflammatory skin diseases other than AD, including seborrheic dermatitis, intertriginous psoriasis, lichen planus and cutaneous lupus erythematosus.

Topical pimecrolimus in the treatment of genital lichen planus: a prospective case series

BACKGROUND

A potent topical steroid is the conventional therapy for genital lichen planus (GLP). Side-effects or steroid resistance can be encountered and second-line therapy such as topical tacrolimus may be required. In our experience tacrolimus may be poorly tolerated in genital skin because of a burning sensation. In addition, there is impairment of Langerhans cell function, raising concerns about its long-term use. These adverse effects may not be as marked with pimecrolimus. To our knowledge, pimecrolimus has not been used in the treatment of GLP.

OBJECTIVES

To assess the efficacy and tolerability of topical pimecrolimus in the treatment of GLP.

METHODS

Eleven women with GLP were recruited: 10 had erosive vulval disease and one had classical lichen planus of perianal skin. Ten patients had poor disease control, and despite using topical steroids appropriately, two of these also had steroid-related side-effects in adjacent unaffected skin. The eleventh patient had adequate disease control but marked steroid atrophy. Topical pimecrolimus 1% cream (Elidel cream; Novartis, Camberley, U.K.) was applied twice daily to affected areas. Patients were followed up between 4 and 6 weeks later. They remain under regular review and at the time of writing mean follow-up is 5.2 months (range 2-10).

RESULTS

Nine patients (82%) tolerated pimecrolimus, including three patients previously intolerant of tacrolimus. These nine patients showed a clinical response at 4-6 weeks: two showed a complete response with no residual disease activity visible and seven had a partial response. With longer follow-up, six (55%) of the women had a complete response and three (27%) were considered to have a partial response. Eight patients noted symptomatic improvement and one felt that her symptoms were the same as with steroid use. Two patients (18%) with erosive lichen planus were unable to tolerate pimecrolimus due to local irritation.

CONCLUSIONS

We have found that topical pimecrolimus 1% cream is an effective treatment for GLP. Local irritation can limit its use, but it may be better tolerated than topical tacrolimus: three of our complete responders had previously been intolerant of tacrolimus. Topical pimecrolimus may be a valuable second-line treatment for patients with steroid-related side-effects or steroid-resistant GLP.