Neurotropic and psychotropic drugs in dermatology

Approach to the pruritic horse

Pruritus in the horse may be due to several causes, the most common being a hypersensitivity response to salivary proteins in the Culicoides genera, which may coexist with atopic dermatitis, also known as an environmental allergy to pollens, molds, dust, storage mites, etc. Less common etiologies are food allergy and contact allergy, the latter often caused by owners applying various products to the skin. Other ectoparasites, such as Chorioptes mites, may also initiate pruritus. Secondary bacterial infections (usually Staphylococcus spp) may be pruritic in and of themselves. This article reviews the questions that need to be asked of owners to obtain a relevant history, always important for any organ system, but perhaps none more so than the skin. The various clinical findings such as alopecia and crusts and their location on the horse, diagnostic methods such as intradermal or serum testing for allergies, and subsequent hyposensitization are also discussed. Therapeutic options currently available for the potential underlying diseases, in particular for the hypersensitivity reactions to Culicoides spp or environmental allergens, are reviewed with the studies of hyposensitization over the last 40 years, as well as medications that may be effective. While the most common causes of pruritus in the horse are known, the current understanding of the pathophysiology still needs to be investigated, and consequently, the most effective treatments for those causes need to be improved. Newer research is discussed that may eventually add to the diagnostic and therapeutic options currently available for the pruritic horse.

Dermatitis Artefacta: A Challenging Case Report

We report a 31-year-old female presented with a history of recurrent skin and oral lesions for 10 years. She brought a histopathology report confirming the diagnosis of pemphigus vulgaris (PV), which was found to be faked with no patient information and lacked letterhead. Skin and oral examination only reveal multiple linear upper lip erosions. We believed the patient had a preliminary diagnosis of PV, and we asked the patient to continue her medications. Based on the conflicting history and occurrence of contradictory issues, a diagnosis of dermatitis artefacta was made. The patient improved after four sessions of dialectical therapy.

Update on Pharmacotherapy in Psychodermatological Disorders

Psychodermatological (PD) conditions encountered in dermatologic practice include primary psychiatric conditions such as delusions of parasitosis or secondary psychiatric conditions such as anxiety and depression due to dermatologic disease. The psychotropics include antipsychotic agents, anti-anxiety agents, antidepressants, and miscellaneous drugs such as anti convulsants. Anti psychotics are further divided into first-generation and second-generation drugs. Currently, second-generation drugs e.g., risperidone are preferred over first-generation drugs e.g., pimozide in delusional infestation owing to the side effect profile of the latter. Anti-anxiety agents include benzodiazepines used in acute anxiety and buspirone in chronic anxiety disorders. They are frequently prescribed along with antidepressants. Although dependence and necessity of tapering is a problem with benzodiazepines, delayed onset of action is a feature of buspirone. The commonly used antidepressants in dermatology include selective serotonin reuptake inhibitors (citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline), selective serotonin norepinephrine reuptake inhibitors (venlafaxine, desvenlefaxine, and duloxetine), norepinephrine dopamine reuptake inhibitors (bupropion), tricyclic antidepressants (doxepin, amitriptyline, imipramine, and clomipramine), and tetracyclic antidepressants (mirtazapine). Miscellaneous drugs include anticonvulsants such as gabapentin and pregabalin, naltrexone, and N-acetyl cysteine. The principles of PD treatment are first establish the psychiatric diagnosis, followed by initiating drug treatment. The choice of drugs is dependent on multiple factors such as side-effect profile, drug interactions, and co-morbid conditions. Usually, drugs are started at a low dose and gradually increased. A literature search was done in Pubmed, Google Scholar, and Medline databases, and articles on treatment were analyzed.

Post-Burn Pruritus

Post-burn pruritus is the pruritus that occurs after burn during the rehabilitation and healing process of burn wounds. The post-burn pruritus is a common and serious complication of burn injury, which severely lowers the quality of life of the patient. Many potential treatments are available for pruritus but there is no consensus of the best single treatment yet. The precise mechanism of post-burn pruritus has not been elucidated, but it appears to have pruritogenic and neuropathic aspects. Clinically, post-burn pruritus tends to be intractable to conventional treatment but rather responds to neuroleptic agents, such as gabapentin and pregabalin. During wound healing, various neuropeptides secreted from the nerves of the skin control epidermal and vascular proliferation and connective tissue cells. When keratinocytes are activated by an itch-inducing substance, they secrete a variety of inflammatory substances that increase the susceptibility of the itch receptor. There are two mechanisms underlying post-burn neuropathic pruritus. The first one is peripheral sensitization. The second one is the intact nociceptor hypothesis. An effective treatment for post-burn pruritus will also be effective in other neuropathic and intractable itching. In this review, we summarized the interaction and mechanism of keratinocytes, immune cells, and nerve fibers related to post-burn pruritus.

Vulvar pruritus-Causes, Diagnosis and Therapeutic Approach

BACKGROUND

In Germany, 17-23% of the population suffers from chronic itching of the skin; in 5-10% of cases, the female genitalia are affected, specifically, the vulva. Vulvar pruritus is thus a common symptom that often markedly impairs the affected women's quality of life.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in MEDLINE/PubMed for articles on the pathogenesis, diagnosis, and treatment of vul- var pruritus. The search terms were (in German and English) "vulvärer Juckreiz," "pruritus vulvae," and "genital itch," alone and in combination with "Behandlung," "Therapie," or "treat- ment."

RESULTS

The most common cause of vulvar pruritus is vulvo- vaginal candidiasis followed by chronic dermatoses, such as lichen sclerosus and vulvar eczema. Especially in refractory cases, an invasive or preinvasive lesion such as squamous epithelial dysplasia (VIN, vulvar intraepithelial neoplasia) should be borne in mind in the differential diagnosis. Rarer causes include infection, atrophy, and vulvodynia. The essen- tial elements of treatment are topical/oral antimycotic drugs and high-potency glucocorticoids, along with consistently ap- plied, basic moisturizing care and the avoidance of potential triggering factors.

CONCLUSION

As vulvar pruritus has multiple causes, standard- ization of its diagnostic evaluation and treatment would be l efficacy and to meet the diverse needs of women who suffer from this condition.

Can we use psychoactive drugs to treat pruritus?

Pruritus is a frequent complaint both in dermatology and general medicine. This burdensome symptom has a complex and multifactorial pathogenesis, with the key involvement of central nervous system in its development. Psychoactive drugs (psychopharmaceuticals) encompass several therapeutic groups utilized mainly in psychiatry. However, these drugs are occasionally used in dermatological practice and may contribute to alleviation of pruritus in a variety of cutaneous and extracutaneous disorders. This review article summarizes the role of H1-antihistamines, antidepressants, antipsychotics and antiepileptics in managing pruritus.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life.

OBJECTIVES

To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables.

MAIN RESULTS

In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding).

AUTHORS' CONCLUSIONS

Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

Pruritus is not the most prevalent but one of the most puzzling symptoms in palliative care patients. It can cause considerable discomfort and has a major impact on patients' quality of life. In the field of palliative care, pruritus is a symptom occurring in patients with disparate underlying diseases and based on different pathologic mechanisms but ending in the same phenomenon. The pathogenesis of pruritus is complex and not fully elucidated. Thus, it is still very difficult to treat pruritus effectively. Evidence-based treatment approaches are needed.

OBJECTIVES

The objective was to evaluate the efficacy of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

A systematic literature search up to January 2012 was performed and it was updated in August 2012. The following databases were searched: The Cochrane Library (CENTRAL, DARE, CDSR) (2012, issue 8 of 12); MEDLINE (1950 to August 2012); EMBASE (1980 to August 2012) and three other databases. In addition, we searched trials registries and checked the reference lists of all relevant studies, key textbooks, reviews, and websites, and contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of different pharmacological treatments on preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified titles and abstracts. Three independent review authors performed assessment of all potentially relevant studies, data extraction, assessment of risk of bias and methodological quality. Results were summarised descriptively according to the different pharmacological interventions and the type of underlying pruritus. Where possible, results were presented in meta-analyses.

MAIN RESULTS

In total, 38 reports comprising 40 studies and 1286 participants were included in the review. Altogether, 30 different treatments for pruritus in four different patient groups were included.The findings of this review indicated that the treatment of pruritus for palliative care patients is challenging and requires an individualistic approach. Results showed that effective therapeutic choices have to be guided by the pathophysiology of the pruritus. Various forms of pruritus occur, especially in the field of palliative care, and sometimes the origin of the pruritus is difficult to determine. Therefore, identifying the underlying cause of pruritus is of prime importance in order to develop tailored treatment plans, even if in palliative care the treatment is focused towards the symptom and not necessarily the underlying disease.Results show that in palliative care patients with pruritus of different natures, treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, may be beneficial. For patients suffering from pruritus associated with HIV infection, indomethacin was described as the most effective drug, although the evidence was weak. For patients suffering from chronic kidney disease-associated pruritus, gabapentin may be an option. An alternative treatment for this patient group seems to be the κ-opioid receptor agonist nalfurafine, which has shown significant amelioration of pruritus and acceptable adverse effects. As they have exhibited a low incidence of adverse effects, rifampicin and flumecinol may be recommended for patients with cholestatic pruritus. The opioid antagonist naltrexone has been shown to offer a therapeutic alternative for patients suffering from uraemic or cholestatic pruritus. However, these drugs are often inappropriate in the palliative population because of the risk of reducing analgesia when giving high doses of naltrexone.

AUTHORS' CONCLUSIONS

The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.

Dermatitis artefacta

A 27-year old lady presented to our department with multiple erosive lesions over extremities, which had a very bizarre pattern and was only over accessible parts of body. A thorough history was taken and a diagnosis of dermatitis artefacta was made. We present this interesting case for its rarity and future reference.

Pruritus: still a challenge

Pruritus is a symptom that may be associated with a wide array of diseases - skin diseases, systemic diseases or even those without a defined cause. According to its severity and evolution, it may compromise the patients' quality of life in a significant way. New therapeutic approaches, in which histamine release is not the main event, are being described for pruritus control. Therefore, taking into account the origin of the mediators of pruritus, we conducted a review of the available resources emphasizing that, although very important, anti-histamines are not the answer for every kind of pruritus.

Psychopharmacology in psychodermatology

BACKGROUND

The management of psychodermatologic disease often involves the use of psychotropics by dermatologists. A general approach to the psychopharmacologic management of psychodermatological disease may be of assistance to the dermatologist.

OBJECTIVE

We review and provide a current psychopharmacologically based approach to management of common psychopathologies associated with psychodermatologic disorders, common side effects, and potential drug interactions that may occur with selected psychotropics.

METHODS

Using relevant MeSH terms, we performed a review of the literature from 1980 to 2006.

RESULTS AND CONCLUSIONS

Effective psychopharmacologic management of psychodermatologic disease involves identifying and basing treatment on the associated psychopathology; familiarity with a variety of psychotropic agents, including antidepressants, anxiolytics, and antipsychotics; and the involvement of a psychiatrist when possible.

Steroids versus other immune modulators in the management of allergic dermatoses

PURPOSE OF REVIEW

The classic role of topical and systemic corticosteroids for allergic dermatoses is discussed, with special attention to the impact on the current clinical treatment paradigm by newer systemic and topical therapies. These products are reviewed and recommendations presented on how to effectively assimilate them into clinical practice.

RECENT FINDINGS

Current knowledge about the etiopathogenesis of atopic dermatitis has resulted in drug development focused on agents with less toxicity than current topical and systemic corticosteroids. Some agents with ceramide/cholesterol/acid combinations demonstrate efficacy in restoring the dysfunctional skin barrier of atopic patients. Concerns resulting from the recent Federal Drug Administration announcement regarding a theoretical risk of cancer associated with topical calcineurin inhibitors are also addressed. Novel therapeutic entities are presented.

SUMMARY

Patients seeking relief from atopic dermatitis have historically had few really effective and safe therapeutic options. Topical calcineurin inhibitors represent an exciting new therapy for atopic dermatitis without the side-effect profile associated with topical corticosteroids. Nonsteroidal formulations incorporating glycyrrhetinic acid/telmesteine/Vitis vinifera extract and palmitoylethanolamide as 'active' ingredients recently entered the market, stressing antipruritic, antiinflammatory, and skin barrier repair. This confabulates against previously designed topical therapy paradigms. These new products may be used as monotherapy or alternatives to steroid agents.

Psychodermatology: a guide to understanding common psychocutaneous disorders

OBJECTIVE

This review focuses on classification and description of and current treatment recommendations for psychocutaneous disorders. Medication side effects of both psychotropic and dermatologic drugs are also considered.

DATA SOURCES

A search of the literature from 1951 to 2004 was performed using the MEDLINE search engine. English-language articles were identified using the following search terms: skin and psyche, psychiatry and dermatology, mind and skin, psychocutaneous, and stress and skin.

DATA SYNTHESIS

The psychotropic agents most frequently used in patients with psychocutaneous disorders are those that target anxiety, depression, and psychosis. Psychiatric side effects of dermatologic drugs can be significant but can occur less frequently than the cutaneous side effects of psychiatric medications. In a majority of patients presenting to dermatologists, effective management of skin conditions requires consideration of associated psychosocial factors. For some dermatologic conditions, there are specific demographic and personality features that commonly associate with disease onset or exacerbation.

CONCLUSIONS

More than just a cosmetic disfigurement, dermatologic disorders are associated with a variety of psychopathologic problems that can affect the patient, his or her family, and society together. Increased understanding of biopsychosocial approaches and liaison among primary care physicians, psychiatrists, and dermatologists could be very useful and highly beneficial.

Mirtazapine for reducing nocturnal itch in patients with chronic pruritus: a pilot study

Nocturnal pruritus is a significant problem for patients with inflammatory skin diseases and many systemic diseases. The oral therapies currently available have a limited effect. We present an open, uncontrolled pilot study of 3 patients with inflammatory skin diseases and severe nocturnal pruritus who underwent treatment with mirtazapine (Remeron), a noradrenergic and specific serotonergic antidepressant. Mirtazapine is a safe medication without serious side effects and may be an effective alternative for the treatment of nocturnal pruritus.

Pimozide in dermatologic practice: a comprehensive review

Pimozide is an antipsychotic drug of the diphenylbutylpiperidine class. In the US, it is FDA-approved only as a backup treatment for Gilles de la Tourette syndrome, although it has been used in other countries for many years as a treatment for schizophrenia. In the past 20 years, pimozide has been found to be especially efficacious in the treatment of monosymptomatic hypochondriacal psychoses and is used by psychiatrists and dermatologists for this off-label purpose. In particular, pimozide is considered the treatment of choice for delusions of parasitosis. In addition, pimozide has been found to be efficacious in the treatment of body dysmorphic disorder, metastatic melanoma, trichotillomania, and trigeminal and postherpetic neuralgia. This review aims to familiarize physicians, especially dermatologists, on the uses of pimozide in dermatologic practice. A review of the literature was performed and the relevant information synthesized to give a complete overview of the drug and its therapeutic uses in dermatology.

Mirtazapine for pruritus

Pruritus is a relatively rare but distressing symptom associated with cholestasis, renal failure, and malignancies. Medical management recently has included the use of ondansetron and paroxetine. We report four patients whose pruritus responded to mirtazapine.

Behavioral dermatology

The practice of behavioral dermatology encompasses the management of any dermatologic condition for which there is a substantial behavioral or emotional component. Commonly recognized behavioral dermatoses such as acral lick dermatitis, psychogenic alopecia, and hyperesthesia are syndromes rather than discrete diagnoses. Successful patient management is dependent upon integrating physiological, social, and environmental factors which contribute to the clinical manifestation of behavioral dermatoses.

Efficacy of naltrexone on acetylcholine-induced alloknesis in atopic eczema

Atopic eczema (AE) is a chronically pruritic inflammatory skin disease. Although the mediators and exact mechanisms eliciting and sustaining pruritus are not completely known, AE patients in clinical trials have been shown to benefit under treatment with morphine antagonists. Naltrexone (NAL) is a relatively pure morphine antagonist that blocks the effects of opioids twice as much as naloxone. NAL exhibits minimal pharmacological activity and displaces endorphines at mu- and kappa-receptors without its own intrinsic activity. NAL's excellent oral bioavailability and linear increases in the area under plasma concentration-time curve make it ideal for use in experimental studies. We designed our present experiments similar to former experiments evaluating both peripheral cutaneous sensations and central itch procession in order to gain more information about the possible distribution of opioid receptors and their involvement in the pathophysiology of pruritus. Eleven AE patients participated in our double-blind study. Either 25 mg of NAL (Nemexin) or a placebo (PLA) was given to the participants 60 min prior to the acetylcholine (ACH) injection [intracutaneous (i.c.) injection of 0.02 ml of 0.55 M]. A PLA stimulus with buffered saline served as control on the opposite forearm. We used laser Doppler flowmetry to measure the vasomotoric changes after ACH injection and recorded the duration and intensity of itch with a visual analogue scale (VAS). Following the evaluation of wheal and flare sensation, we obtained the area of itchy skin around the injection site (alloknesis) by gently stroking the surrounding skin with a brush in the centripetal direction towards the injection site. The results were planimetrically evaluated. Oral NAL reduced the perifocal itch significantly (P < 0.009). In four of our observations the area of alloknesis completely disappeared. Itch duration was reduced by 20 s and the intensity of itch was diminished, yet not significantly. NAL had no significant effects on cholinergic vasoreactions measured by the laser Doppler (P > 0.50) and especially failed to decrease the initial flux response, which is a typical sign of an altered vascular reaction (P > 0.25). The decrease of wheal (P = 0.008) and flare (P = 0.01) extension indicates an appropriate dosage of our treatment for this experiment. The most significant effects of NAL were observed in parameters of itch processing such as alloknesis (P = 0.009) and flare extension (P = 0.01). Therefore we favour the concept that NAL might have a stronger impact on central nervous mechanisms than on peripheral nociceptive structures.