Psychological influences in psoriasis

It has long been recognized that living with a chronic condition, such as psoriasis, can have considerable impact on the individual concerned. In turn there is increased understanding that the psychological distress encountered as a result of this experience can have implications for the course of the disease. This short review takes this as a starting point and reviews psychological influences in psoriasis. The nature of the link between psoriasis and stress is explored and its implications for the patient are discussed in psychological and clinical terms. There seems little doubt that stress, either environmental or psoriasis induced, impacts on our patients and has important implications for the management of psoriasis.

A Short-Term Screening Protocol, Using Fibrillin-1 as a Reporter Molecule, for Photoaging Repair Agents

Photoaged skin is characterized by coarse and fine wrinkles. The mechanisms of wrinkle formation are undetermined, but appear to be due to changes within the matrix of the dermis and at the dermal-epidermal junction. Previous studies have identified marked reductions in procollagens I and III, collagen VII, and the fibrillin-rich microfibrillar apparatus in this area. Topically applied all-trans retinoic acid can repair photoaged dermal matrix, but this takes at least 6 mo of treatment. In this study, we have examined the abundance and distribution of fibrillin-1 prior to, and following, 192 wk of all-trans retinoic acid treatment. We have further developed a short-term protocol to determine the utility of potential repair agents, using fibrillin-1 as the marker for outcome. Individuals with clinically assessed severe photoaging were recruited to the study (n = 8). 0.025% all-trans retinoic acid, 5% sodium lauryl sulfate (irritant control), or vehicle were applied under occlusion to photoaged extensor forearm. A fourth control area was also occluded. After 96 h, punch biopsies were taken under local anesthesia and processed for either transmission electron microscopy or snap frozen. Frozen sections were prepared for immunohistochemistry and in situ hybridization immunohistochemistry. Electron microscopy revealed aberrant elastic fibers in the papillary dermis of photoaged forearm skin, with sparse microfibrillar apparatus and interstitial collagen. After application of 0.025% all-trans retinoic acid, there was increased deposition of both these dermal matrix components, with the aberrant elastic fibers no longer apparent. Significant increases (p < 0.05) were observed at the protein and mRNA levels for fibrillin-1 following all-trans retinoic acid and sodium lauryl sulfate treatments, with all-trans retinoic acid having a significantly greater effect than irritant control (p < 0.001); however, neither application had significant effect on the abundance of collagen VII or its mRNA. Investigation of collagen I synthesis revealed no difference following treatments. To ascertain the clinical relevance of using fibrillin-1 as a marker for photoaging, facial skin was biopsied at baseline and after long-term (192 wk) topical all-trans retinoic acid treatment (n = 5). Biopsies were wax-embedded and sections prepared for immunohistochemistry for fibrillin-1. Significant increases in the abundance of the microfibrillar apparatus was observed proximal to the dermal- epidermal junction (p < 0.001) following long-term all-trans retinoic acid application. This study indicates that all-trans retinoic acid can significantly affect fibrillin-1 content in photoaged skin. Furthermore, fibrillin-1 can be used as a "reporter" molecule in short-term protocols for testing the utility of topical agents in the repair of photoaged skin.

Activation of oral keratinocytes by mercuric chloride: relevance to dental amalgam-induced oral lichenoid reactions

BACKGROUND

Despite the benefits of mercury-containing amalgam dental fillings there are growing concerns regarding the potential adverse health effects arising from exposure to mercury released from fillings. In some individuals this process may result in a local lichenoid reaction of the oral mucosa.

OBJECTIVES

The aim of this study was to investigate the possibility that mercury salts released from amalgam fillings might act directly on oral keratinocytes to induce changes that could promote the development of such lesions.

METHODS

In vitro experiments were performed in which normal oral and cutaneous keratinocytes were cultured in the presence of mercuric chloride (HgCl2). ICAM-1 expression and the release of cytokines was determined by enzyme-linked immunosorbent assay techniques. T-cell binding to HgCl2-pretreated keratinocytes was assessed using a colorimetric method.

RESULTS

Subcytotoxic concentrations of HgCl2 induced a concentration-related increase in ICAM-1 expression and consequent T-cell binding on oral, but not cutaneous, keratinocytes. HgCl2 also stimulated the release of low levels of tumour necrosis factor-alpha and interleukin-8 (but not RANTES), and inhibited the release of interleukin-1alpha by oral keratinocytes.

CONCLUSIONS

This study provides evidence that oral keratinocytes may play an integral part in initiating the pathogenesis of amalgam-induced lichenoid reactions.

Intermittent short courses of cyclosporine microemulsion for the long-term management of psoriasis: a 2-year cohort study

BACKGROUND

Cyclosporine is effective in psoriasis, but long-term continuous therapy may be limited by renal impairment and hypertension. Intermittent short courses of treatment should minimize side effects and improve the risk-benefit ratio.

OBJECTIVE

Our purpose was to assess the long-term efficacy and safety of intermittent short courses of the microemulsion formulation of cyclosporine (Neoral) in the management of chronic plaque psoriasis unresponsive to topical therapies.

METHODS

In a multicenter open cohort study, 76 subjects were treated intermittently over a 2-year period. Patients with chronic plaque psoriasis were treated with cyclosporine until clearance of psoriasis or for a maximum of 12 weeks. Patients were then randomized into two groups. Group A stopped cyclosporine abruptly, whereas group B had the dose reduced by 1 mg/kg per day each week until cessation, which was within 4 weeks. On relapsing, patients received further courses of cyclosporine. Intermittent treatment was continued in this way for 2 years.

RESULTS

There was no statistically significant difference in the percentage of time in remission during the 2-year period between patients randomized to stop cyclosporine abruptly (56.2%) and patients randomized to taper cyclosporine within 4 weeks (61.8%). The mean percentage of time that patients received treatment during the study was 40.5% for randomization group A, 46.2% for randomization group B, and 42.8% overall. The median time to relapse was 115.5 days after the first treatment course but became progressively shorter after multiple treatment courses. Mean blood pressure and serum creatinine levels did not show any clinically significant changes over time.

CONCLUSIONS

This study indicates that intermittent short courses of cyclosporine are effective in patients with moderate to severe psoriasis for up to 2 years while improving the safety profile relative to continuous cyclosporine monotherapy.

Cytokine gene polymorphisms in psoriasis

BACKGROUND

Cytokine production is under genetic control, and certain allelic variants of cytokine genes are associated with higher or lower cytokine production in vitro and in vivo. Psoriasis is associated with an overexpression in the involved skin of T-helper cell type 1 (Th1) cytokines, e.g. interferon (IFN) -gamma and tumour necrosis factor (TNF) alpha and relative underexpression of Th2 cytokines, e.g. interleukin (IL) -4 and IL-10. Objective We investigated the hypothesis that allelic variants of genes for a high production of Th1 cytokines or TNF-alpha, or conversely low production of Th2 cytokines might represent a risk factor for developing psoriasis.

METHODS

Genotyping for IFN-gamma, IL-10, IL-4 and TNF-alpha was undertaken for 84 patients with psoriasis and compared with control data on file.

RESULTS

Genotype frequencies showed no differences between patients and controls for IFN-gamma, TNF-alpha or IL-4. For IL-10, patients with late onset psoriasis (over 40 years) were more likely to be heterozygous at position - 1082 (P = 0.02), corresponding to intermediate production of IL-10 in vitro and in vivo.

CONCLUSIONS

Psoriasis is not determined by a genotype consistent with high production of Th1 cytokines or low production of Th2 cytokines. Thus, the Th1 cytokine profile found in psoriatic plaques is most likely a consequence of local factors.

Psoriasis: the future

The aetiology of psoriasis is still unclear but our knowledge of the psoriatic process has grown substantially over the last two decades. The future will undoubtedly bring advances in our understanding of the pathogenesis of psoriasis and, as a consequence, new therapies. Defining the molecular genetics of psoriasis will enhance our understanding of the disease process and hopefully facilitate the development of a representative animal model. This in itself will be a key step in the development and testing of new therapies. Precise identification of the immunological events involved in psoriasis will allow specific T-cell- and cytokine-targeted, and perhaps less toxic. immunotherapies. Anti-angiogenic agents that are in development for use in oncology may also be effective in psoriasis. The adaptation of current topical therapies such as retinoids and vitamin D analogues to produce more effective and better-tolerated formulations will also play a significant role in our future first-line management of patients. The increased recognition and better management of environmental trigger factors such as psychological distress will become an important factor in future psoriasis care. The development of physical therapies including photodynamic therapy and excimer lasers has the potential to expand the remit of psoriasis therapy. There is little doubt that the future for our patients with psoriasis is bright. However, this will only be achievable by a concerted research effort to understand all facets of this enigmatic disease ranging from the molecular to the environmental.

Exogenous topical lactoferrin inhibits allergen-induced Langerhans cell migration and cutaneous inflammation in humans

BACKGROUND

Lactoferrin (LF), an iron-binding protein found in exocrine secretions, is known to possess antibacterial properties. It has recently been proposed that LF may also influence inflammatory reactions.

OBJECTIVES

To characterize in humans the ability of recombinant homologous LF to inhibit the induced migration of epidermal Langerhans cells (LCs) from the skin, a process known to be dependent upon the proinflammatory cytokines tumour necrosis factor (TNF)-alpha and interleukin 1beta and to influence cutaneous inflammatory reactions.

METHODS

We investigated the anti-inflammatory properties of LF in human volunteers.

RESULTS

Topical exposure to LF 2 h prior to sensitization caused a significant reduction in contact allergen (diphenylcyclopropenone, DPC)-induced LC migration from the epidermis as judged by the altered frequency of cells expressing either HLA-DR or CD1a determinants. That this reduction was secondary to an inhibition of TNF-alpha production was indicated by the fact that LF failed to influence LC migration induced by intradermal injection of this cytokine. In approximately 50% of those volunteers who displayed local inflammation in response to DPC, LF was found to cause a discernible reduction in the clinical severity of the reaction, associated with reduced infiltration of inflammatory cells.

CONCLUSIONS

These data demonstrate that LF is able to influence cutaneous immune and inflammatory responses, possibly because of an impaired production of local proinflammatory cytokines.

Distribution and expression of type VI collagen in photoaged skin

BACKGROUND

Several of the characteristic clinical features of photoaged skin, including wrinkling, are thought to be dependent on changes in the dermal matrix brought about by chronic sun exposure. Such changes include reductions in collagens I, III and VII, an increase in elastotic material in the reticular dermis and a marked reduction in the microfibrillar glycoprotein fibrillin.

OBJECTIVES

To examine whether type VI collagen, a microfibrillar collagen necessary for cell-cell and cell-matrix communication, is affected by the photoageing process.

METHODS

Six healthy volunteers with moderate to severe photoageing were enrolled into the study. Immunohistochemistry and in situ hybridization histochemistry were used to examine the levels of type VI collagen in photoprotected and photoaged sites.

RESULTS

In photoprotected skin, type VI collagen was concentrated in the papillary dermis immediately below the dermal-epidermal junction, around blood vessels, hair follicles and glandular structures. The distribution of type VI collagen was unchanged in photoaged skin, although we observed an increase in the abundance of the alpha3 chain of collagen VI in the upper papillary dermis, at its junction with the dermal-epidermal junction (P < 0.05). No alterations were observed for any alpha chain at the mRNA level.

CONCLUSIONS

These studies suggest that chronic sun exposure (photoageing) has little or no effect on either the distribution, abundance or levels of expression of type VI collagen in human skin. Thus, type VI collagen, unlike other matrix components so far studied, appears to be relatively unaffected by the photoageing process.

Topical tacrolimus in the management of peristomal pyoderma gangrenosum

BACKGROUND

Peristomal pyoderma gangrenosum (PPG) is a potentially disabling disease in stoma patients. Topical tacrolimus has been shown to be effective in the management of pyoderma gangrenosum. Unfortunately, greasy topical treatments may be impractical for PPG because of impaired appliance adhesion.

OBJECTIVE

The purpose of this open study was to evaluate the therapeutic effectiveness of topical tacrolimus 0.3% formulated in carmellose sodium paste compared with topical corticosteroid preparations in the management of PPG.

RESULTS

A total of 11 patients with PPG received treatment with topical tacrolimus 0.3% in Orabase trade mark and 13 with topical clobetasol propionate 0.05% as monotherapy in each case. Seven of the tacrolimus-treated group healed completely (mean time to healing: 5.1 weeks) compared with five of the clobetasol propionate-treated group (mean time to healing: 6.5 weeks). Topical tacrolimus was significantly more effective than clobetasol propionate in managing larger PPG lesions (ulcer diameter > 2 cm). In six patients, who had failed to respond adequately to multiple systemic and topical treatments for PPG, the addition of topical tacrolimus was associated with healing of PPG within 6 weeks.

CONCLUSION

These results suggest that topical tacrolimus 0.3% in Orabase trade mark is a more effective and expeditious treatment than clobetasol propionate 0.05% for PPG. It is significantly more effective than clobetasol propionate 0.05% in managing lesions larger than 2 cm in diameter. Topical tacrolimus may be highly effective when other systemic or topical treatments have been unsuccessful.

Successful treatment of severe recalcitrant psoriasis with combination infliximab and methotrexate

Plaques of psoriasis contain increased levels of cytokines, including tumour necrosis factor-alpha (TNF-alpha), which are thought to be essential to the maintenance of the psoriatic process. We report the successful treatment of severe, recalcitrant psoriasis when infliximab (a monoclonal antibody to TNF-alpha) was used in combination with methotrexate.

The contribution of perceptions of stigmatisation to disability in patients with psoriasis

OBJECTIVE

The aim of the present study was to assess the significance of general and psoriasis specific psychological variables in patients with psoriasis and to examine the relative importance of disease status and these psychological variables in predicting psoriasis-related disability.

METHOD

A total of 115 patients with psoriasis underwent clinical assessment and completed a number of psychological and psoriasis specific questionnaires.

RESULTS

High levels of self-reported distress were identified with 43% and 10% of patients scoring as probable cases on the Hospital Anxiety and Depression Scale (HADS) subscales of anxiety (mean 9.3+/-4.9) and depression (mean 4.8+/-3.7), respectively. Multiple regression analysis indicated that clinical severity of psoriasis and anatomical area of involvement had no impact on psychological distress and disability. Perceptions of stigmatisation were significantly related to both psychological distress and degree of disability (P's<.001) and accounted for a significant amount of the variance in disability over and above general psychological distress (F change=11.03; P<.001).

CONCLUSION

Psychological factors were much stronger determinants of disability in patients with psoriasis than disease severity, location or duration. This has important implications in relation to the clinical management of psoriasis.

Combination regimens of topical calcipotriene in chronic plaque psoriasis: systematic review of efficacy and tolerability

OBJECTIVE

To examine the efficacy and tolerability of calcipotriene combined with phototherapy or systemic therapies compared with monotherapy for the treatment of chronic plaque psoriasis.

DESIGN

Quantitative systematic review of 11 randomized controlled trials involving a total of 756 patients with plaque psoriasis.

MAIN OUTCOME MEASURES

Rate ratios (RRs) for marked improvement or clearance in patient and investigator overall assessments of response; mean difference in percentage change in Psoriasis Area and Severity Index; and RRs for clearance in patient and investigator overall assessments of response. Adverse effects were estimated with the RR and the rate difference in terms of withdrawal rate, proportion of patients experiencing adverse events, and proportion of patients with cutaneous and noncutaneous adverse effects.

RESULTS

Antipsoriatic effects of acitretin, cyclosporine, and psoralen-UV-A phototherapy were enhanced with the addition of topical calcipotriene using the Psoriasis Area and Severity Index as the outcome, but this is not translated into an increase in the number of patients who achieve at least marked improvement. At the end of treatment, the RRs for marked improvement or clearance in patient assessments were as follows: calcipotriene plus acitretin vs acitretin alone (12 weeks), 1.4 (95% confidence interval [CI], 1.0-1. 9); calcipotriene plus cyclosporine vs cyclosporine alone (6 weeks), 1.2 (95% CI, 0.9-1.6); and calcipotriene plus psoralen-UV-A vs psoralen-UV-A alone (12 weeks), 1.2 (95% CI, 0.9-1.6). Patients were also no more likely to obtain marked improvement or better with calcipotriene plus UV-B therapy than with UV-B therapy alone (RR, 1. 0; 95% CI, 0.8-1.1 at 8 weeks in the patient assessment). There is limited evidence that use of calcipotriene might reduce the cumulative exposure to phototherapy and systemic treatment. During the short duration of these trials, there were no significant differences in withdrawal rates or adverse effects between the combined regimens and their corresponding monotherapy control interventions.

CONCLUSIONS

Overall, there is insufficient evidence to support any large effects in favor of combination treatment. In the patient assessments, the results do not show an adjuvant effect, but there is some evidence that use of calcipotriene might reduce cumulative exposure to systemic therapy to obtain clearance. There were no long-term morbidity data on the effectiveness of any of the combinations studied. Given that psoriasis is a chronic recurrent disease for most patients, longer trials are needed to determine whether the addition of topical calcipotriene to systemic therapy improves the risk-benefit ratio by reducing the long-term risk of toxic effects. Equally important is the need to examine the impact of such combinations on the duration of remission after treatment.

The spectrum of skin disorders in abdominal stoma patients

BACKGROUND

Skin integrity is essential for the normal usage of a stoma appliance. However, there is little published on the prevalence, nature or management of stoma-related skin disorders. Objectives To document stoma-related skin disorders in a large cohort of patients.

METHODS

We sent a postal questionnaire to all surviving patients who had had abdominal stoma surgery at Hope Hospital, Salford, U.K. in the 10 years from 1 January 1989. Those reporting skin disease were invited to attend a clinic run by a dermatologist and a stoma-care specialist nurse. All lesions were categorized and swabs taken for microbiological examination.

RESULTS

Of 525 surviving patients, 325 (62%) replied to the questionnaire. Of these, 73% reported a skin problem that had affected normal stoma bag use. Dermatoses included irritant reactions, particularly from leakage of urine or faeces (42%); pre-existing skin diseases, principally psoriasis, seborrhoeic dermatitis and eczema (20%); infections (6%); allergic contact dermatitis (0.7%) and pyoderma gangrenosum (0.6% annual incidence). A further 15% of patients with skin problems had persistent or recurrent dermatitis not explained by allergy, frank infection or faecal irritation. This responded to short-term treatment with topical corticosteroids. Further investigation is under way into its pathogenesis.

CONCLUSIONS

Skin disorders are common in stoma patients, and various patterns can be recognized and effectively treated.

Investigation of cytomegalovirus and human herpes viruses 6 and 7 as possible causative antigens in psoriasis

Psoriasis is probably a T-cell-mediated autoimmune disease. Infectious models of autoimmune diseases have been proposed and in psoriasis, it has been suggested that there may be molecular mimicry between streptococcal antigens and epidermal keratins. The immunological profile of stable psoriasis plaques suggests, however, that viral antigens may be important. We investigated, using polymerase chain reaction techniques, whether DNA from either cytomegalovirus (CMV) or human herpes viruses (HHV) 6 and 7 is present in the skin of patients (n = 10) with chronic plaque psoriasis. We also investigated 29 patients for the presence of serum IgG to CMV. We found no evidence of CMV or HHV 7 DNA in psoriasis plaques although DNA for HHV 6 was detected in both involved and uninvolved skin in 1 out of 10 patients. There was no statistically significant increase in prior CMV infection, as assessed by the presence or absence of serum IgG to CMV, in psoriasis, compared to our local population. Although there is circumstantial evidence that viral antigens may be important in the pathogenesis of psoriasis we found no evidence to link infection with CMV or HHV 6 and 7 with subsequent development of chronic plaque psoriasis.

Cost-effectiveness analysis of topical calcipotriol versus short-contact dithranol. In the treatment of mild to moderate plaque psoriasis

OBJECTIVE

To examine the relative cost effectiveness of topical calcipotriol and short-contact dithranol in the treatment of mild to moderate plaque psoriasis.

DESIGN AND SETTING

This was a modelling study from the perspective of the UK National Health Service as payer.

METHODS

The interventions were compared using 2 decision-analytic models: one using a short term horizon (12 weeks) and the other using a longer term horizon (up to 1 year). Clinical success of treatment and relapse rates were obtained from the results of randomised controlled trials.

MAIN OUTCOME MEASURES AND RESULTS

The outcome measure used was the degree of improvement in psoriasis as judged by the patient. In the short term comparison, calcipotriol was the most effective treatment (60.8% success), but it was also the most expensive (96.03 Pounds; 2000 values). The incremental cost per success was 577.50 Pounds using a 12-week course of calcipotriol compared with short-contact dithranol. Over the long term horizon, first-line treatment with calcipotriol still had the highest expected cost per successful treatment (164.91 Pounds), but the incremental cost using this strategy was 38.66 Pounds compared with short-contact dithranol. In terms of cost per successful day's treatment (i.e. the cost for a day in which the patient reported a marked improvement or cleared lesions), the cost of each additional successful day's treatment was 19.93 Pounds when using calcipotriol as first-line treatment rather than short-contact dithranol.

CONCLUSION

The combination of differences in drug acquisition costs and relapse rates can lead to large differences in the comparative cost effectiveness of topical treatments for plaque psoriasis. From the perspective of the prescriber, the results of this analysis suggest that selecting short-contact dithranol as first-line treatment was the most cost-effective strategy.

Topical sucralfate in the management of peristomal skin disease: an open study

Dermatoses affecting the skin around stoma sites are common and difficult to treat. We have investigated the effectiveness of topical sucralfate in the management of peristomal dermatoses in adults using an open study design. Apart from forming a physical barrier to further irritation, sucralfate binds to basic fibroblast growth factor preventing its degradation and thereby promotes healing. In eight out of nine patients with faecal or urine erosions, daily, topical sucralfate treatment was associated with healing within 4 weeks. There was limited or no response to treatment in a further nine patients with traumatic ulcers, excoriated dermatitis or pyoderma gangrenosum. Topical sucralfate represents a safe, inexpensive and effective therapeutic intervention, particularly for those patients with high output or short stomas where repeated stoma leakage may be unavoidable.

Peristomal dermatoses: a novel indication for topical steroid lotions

BACKGROUND

Dermatoses that interfere with the normal use of a stoma appliance are common. When preventable causes, such as infection or allergy, are not identified, barrier preparations or topical steroids have been used. However, topical medicaments formulated in a cream or ointment base will cause stoma bags to detach, resulting in leaks.

OBJECTIVE

Our purpose was to investigate the efficacy and suitability of corticosteroids in aqueous/alcohol lotions in the management of peristomal dermatoses.

METHODS

A clinic run by a dermatologist and 2 stoma nurses was created. Patients with a variety of noninfective, inflammatory dermatoses were treated with topical corticosteroid lotions up to a maximum of 4 weeks, with occasional use thereafter in some cases.

RESULTS

Topical, aqueous/alcohol, corticosteroid lotions have been used in 60 patients and have proved particularly useful for the treatment of irritant dermatitis, pyoderma gangrenosum, psoriasis, and constitutional eczema. After the initial treatment course, occasional applications, approximately every 2 weeks, may be necessary to control the skin disorder. This low frequency of application minimizes the risk of side effects so that we have not identified local or systemic side effects in any of the patients treated so far.

CONCLUSION

Topical corticosteroids formulated in aqueous alcohol lotion are effective and acceptable treatments for peristomal dermatoses. If used appropriately, the risk of side effects is low.

Basal cell carcinoma

BACKGROUND

Basal cell carcinoma (BCC) is characterized by marked interpatient variation in tumor accrual. The authors previously reported that presentation with a cluster of BCC is associated with an inherited predisposition to develop many additional lesions suggesting clustering is a critical event. A cluster is defined as the presence of two or more new, primary BCCs, at initial or later presentation.

METHODS

The authors recruited 927 cases and determined whether 1) clustering was an early or late event and 2) tumor accrual was altered after clustering.

RESULTS

In the cases, 669 patients developed only 1 lesion, 112 patients presented more than once but with single lesions (single presentation phenotype[SPP]-more), 94 cases had a cluster at first presentation (multiple presentation phenotype [MPP]-cluster initial), and 52 cases first presented with 1 lesion but later had a cluster (MPP-cluster later). The authors found that 1) clustering occurred relatively late. The mean ages at first presentation with 1 BCC of the SPP-more (61.5 years) and MPP-cluster later patients (60.4 years) were similar although presentations with clusters in the MPP-cluster initial (67.6 years, P = 0.0002) and -cluster later cases (68.1 years, P = 0.002) occurred significantly later. 2) Clustering was associated with increased accrual. Thus, 26 patients (MPP-cluster later/a) in the MPP-cluster later group had a additional BCC postcluster. Mean accrual post-cluster (1.99 BCC/year) in these cases was significantly increased (P = 0.0001) compared with precluster accrual (0.39 BCC/year).

CONCLUSIONS

The authors found that the formation of BCC clusters represents a critical event such that after a cluster presentation, tumor accrual is significantly increased. Cluster presentation is a relatively late event suggesting reduced effectiveness in immune surveillance.

Langerhans cell migration

Epidermal Langerhans cells (LC) play pivotal roles in the induction of cutaneous immune responses. Encounter with antigen in the skin, or other stimuli, cause the mobilization of LC and their migration, via afferent lymphatics, to draining lymph nodes where they localize within the paracortex. During their movement from the skin LC acquire the characteristics of immunostimulatory dendritic cells (DC) such that the antigen-bearing cells which accumulate in lymph nodes are able to provoke specific T-lymphocyte responses. Epidermal cytokines initiate and regulate LC migration (and maturation), of particular importance being interleukin-1beta and tumour necrosis factor-alpha. Collectively, these cytokines, together with relevant chemokine receptor-ligand interactions, effect the liberation of LC from the epidermis and their directed movement to, and localization within, peripheral lymph nodes. Described here are the phenotypic changes induced during the activation of LC and the mechanisms through which their migration is regulated.

'Brooke of Manchester'

We present a brief account of the life and times of Dr Henry Grundy Brooke, a Manchester dermatologist and key figure in British dermatology in the nineteenth century. Our report highlights the achievements of a man whose contributions to dermatology continue to be of relevance in the new millennium.

Parastomal pyoderma gangrenosum: clinical features and management

BACKGROUND

The importance of pyoderma gangrenosum (PG) as a cause of ulceration around abdominal stomas is not well recognized.

OBJECTIVE

Our purpose was to describe the incidence, clinical and histologic features, disease associations, and possible risk factors for parastomal PG.

METHODS

A clinic, run by a dermatologist and two stoma nurses, was created. Five hundred patients approached by postal questionnaire were invited to attend if they had skin problems. In addition, local surgical, dermatologic, and nursing services were invited to refer patients with parastomal skin problems. Cases of parastomal PG were identified, investigated, and treated.

RESULTS

The annual incidence of parastomal PG in the questionnaire-based cohort of patients was 0.6% (3 patients). An additional 23 patients with the condition were seen. No consistent hematologic, biochemical, immunologic, microbiological or histologic abnormalities were identified. Local skin damage did not appear to be an important trigger for parastomal PG. The condition is recurrent in one third of cases. Topical tacrolimus (0.3% in carmellose sodium paste) has been effective in 4 patients.

CONCLUSION

Parastomal PG is far more common than previous reports would suggest, and it may be associated with diseases other than inflammatory bowel disease.

The use of folic acid supplementation in psoriasis patients receiving methotrexate: a survey in the United Kingdom

There is little literature on the use of folic acid supplementation in psoriasis patients being treated with methotrexate. Under the auspices of the British Association of Dermatologists we surveyed, using a questionnaire, the use of folic acid supplementation with methotrexate therapy for psoriasis by dermatologists in the UK. Six-hundred and fifteen questionnaires were sent and 153 responses were received (25%). One-hundred and fourteen of the responders (75%) used folic acid supplementation with methotrexate in psoriasis patients. Thirty (26%) of these used folic acid supplementation in all patients taking methotrexate and 84 (74%) used folic acid only under certain circumstances, the most common of which was an elevated erythrocyte mean corpuscular volume. Forty-six per cent of respondents believed that folic acid supplementation reduced nausea and 60% believed that folic acid did not interfere with the efficacy of methotrexate. A wide variety of dosing regimens were used for folic acid supplementation. In the absence of guidelines and controlled trials, there is great variation in the indication for use, dosing regimens used and beliefs regarding methotrexate supplementation for psoriasis. Randomized controlled trials are necessary to address these questions.

Nailfold video capillaroscopy in psoriasis

Changes in the microvasculature are considered to play an important part in the pathogenesis of psoriasis and its associated arthritis. The novel method of nailfold video capillaroscopy is an extension of the technique of widefield nailfold microscopy which has been of diagnostic and predictive use in the in vivo study of the microcirculation in systemic sclerosis and other connective tissue disorders. However, similar studies in patients with psoriasis and psoriatic arthritis and/or nail changes have produced conflicting results. We tested the hypothesis that any abnormalities in nailfold capillaries of either a quantitative or qualitative nature might be observed more readily in subjects with pathology adjacent to the nailfold, i.e. distal interphalangeal (DIP) joint changes and/or nail dystrophy, when using this technique. Forty-four patients with psoriasis were recruited (21 males, 23 females). Twelve patients had psoriasis alone, 13 had psoriasis and nail changes, six had DIP joint involvement with changes of psoriasis elsewhere, and 13 had psoriasis, DIP arthritis and nail changes. Capillary density and standard capillary dimensions were studied and compared with those of 44 age- and sex-matched control subjects. There was a significant (P < 0.05) decrease in capillary loop density in patients with either psoriasis plus nail disease (14.5 +/- 5.7 capillaries per 3 mm field) or psoriasis plus nail and DIP joint disease (14.3 +/- 5. 0) when compared with controls (19.2 +/- 3.8). In patients with psoriatic arthritis affecting the DIP joints, there was a statistically significant (P < 0.05) decrease in arterial and venous capillary limb diameters, and this was also seen in those with arthritis associated with nail changes. However, there was no difference in capillary dimensions between patients with psoriasis and/or nail changes when compared with normal controls. Morphological abnormalities previously described in the literature were not noted in any of our four patient groups. Our findings of diminution in both nailfold capillary bed density and dimensions of the arterial and venous capillary limbs suggest that vascular injury, previously noted in ultrastructural studies, may play a part in the pathogenesis of psoriatic arthritis. However, in contrast to previous studies, we found no specific pattern of a morphological nature of nailfold capillaries in patients with psoriasis with or without nail changes, when compared with normal controls.

Systematic review of comparative efficacy and tolerability of calcipotriol in treating chronic plaque psoriasis

OBJECTIVES

To evaluate the comparative efficacy and tolerability of topical calcipotriol in the treatment of mild to moderate chronic plaque psoriasis.

DESIGN

Quantitative systematic review of randomised controlled trials.

SUBJECTS

6038 patients with plaque psoriasis reported in 37 trials.

MAIN OUTCOME MEASURES

Mean difference in percentage change in scores on psoriasis area and severity index, and response rate ratios for both patients' and investigators' overall assessments of marked improvement or better. Adverse effects were estimated with the rate ratio, rate difference, and number needed to treat.

RESULTS

Calcipotriol was at least as effective as potent topical corticosteroids, calcitriol, short contact dithranol, tacalcitol, coal tar, and combined coal tar 5%, allantoin 2%, and hydrocortisone 0.5%. Calcipotriol caused significantly more skin irritation than potent topical corticosteroids (number needed to treat to harm for irritation 10, 95% confidence interval 6 to 34). Calcipotriol monotherapy also caused more irritation than calcipotriol combined with a potent topical corticosteroid (6, 4 to 8). However, the number needed to treat for dithranol to produce lesional or perilesional irritation was 4 (3 to 5). On average, treating 23 patients with short contact dithranol led to one more patient dropping out of treatment owing to adverse effects than if they were treated with calcipotriol.

CONCLUSIONS

Calcipotriol is an effective treatment for mild to moderate chronic plaque psoriasis, more so than calcitriol, tacalcitol, coal tar, and short contact dithranol. Only potent topical corticosteroids seem to have comparable efficacy at eight weeks. Although calcipotriol caused more skin irritation than topical corticosteroids this has to be balanced against the potential long term effects of corticosteroids. Skin irritation rarely led to withdrawal of calcipotriol treatment. Longer term comparative trials of calcipotriol versus dithranol and topical corticosteroids are needed to see whether these short term benefits are mirrored by long term outcomes such as duration of remission and improvement in quality of life.

The Salford Psoriasis Index: an holistic measure of psoriasis severity

We have developed, tested and validated a new scoring system for psoriasis: the Salford Psoriasis Index (SPI). The SPI incorporates the current clinical extent of psoriasis based on the Psoriasis Area and Severity Index (PASI), a score indicating psychosocial disability, and past severity based on treatment history. The resultant three-figure SPI (signs, psychosocial disability, interventions) is a similar paradigm to the TNM (tumour, nodes, metastasis) classification used for cancer staging. The first figure transforms the PASI into a number from 0 to 10 reflecting extent of psoriasis. The second assesses the psychosocial impact of psoriasis on each patient using a 0-10 visual analogue scale. The third figure reflects historical severity of disease as judged by the need for systemic treatment, admission to hospital and number of episodes of erythroderma. The SPI was prospectively employed in assessing 150 consecutive patients with psoriasis. Furthermore, in a separate cohort of 100 patients we tested the Psychosocial Impact Score against a recognized self-report psoriasis-specific measure, the Psoriasis Disability Index. There was a strong correlation between the two (r = 0.59, P < 0.001). However, the Psychosocial Impact Score correlated poorly with clinical extent scores such as the PASI (r = 0.28, P < 0.05) and the Self-administered PASI in 72 patients tested (r = 0.19, P = 0.1). There was a high correlation between all six observers in 20 patients for both PASI (r = 0.71; 95% confidence interval, CI 0.51-0.86) and the Extent Score (r = 0.70; 95% CI 0. 56-0.89). We believe that the SPI will be more relevant to real-life categorization of psoriasis severity in that it takes an holistic approach based not only on physician assessment but also psychological disability and treatment resistance.

Cytokines and chemokines in the initiation and regulation of epidermal Langerhans cell mobilization

Langerhans cells (LC) are members of the wider family of dendritic cells. LC reside in the epidermis where they serve as sentinels of the immune system, their responsibilities being to sample the external environment for changes and challenges and to deliver information (antigen) to responsive T lymphocytes within skin draining lymph nodes. The ability of LC to migrate from the epidermis to regional lymph nodes is therefore of pivotal importance to the induction of cutaneous immune responses. The journey that LC have to make from the skin has a number of requirements. Initially it is necessary that LC disassociate themselves from surrounding keratinocytes and are liberated from other influences that encourage their retention in the epidermis. Subsequently, migrating LC must successfully traverse the basement membrane of the dermal-epidermal junction and make their way, via afferent lymphatics, to draining lymph nodes. Effective entry into lymph nodes is necessary, as is correct positioning of cells within the paracortex. There is increasing evidence that both cytokines and chemokines, and their interaction with appropriate receptors expressed by LC, orchestrate the mobilization and movement of these cells. We here consider the parts played by these molecules, and how collectively they induce and direct LC migration.

Therapeutic strategies for psoriasis

Psoriasis is a chronic, inflammatory, hyperproliferative skin disease that affects approximately 1-2% of the general population in the U.K. and U.S.A. It is rarely life-threatening, but causes considerable patient morbidity. The disease waxes and wanes, with substantial variability both between and within individual patients. There is no cure for psoriasis; therefore, the aim of treatment is to minimize the extent and severity of the disease to the point at which it no longer disrupts substantially the patient's quality of life. We review the current treatment options, which include topical therapies, phototherapy and systemic agents. Lack of efficacy, adverse effects and aesthetic problems limit the use of many topical therapies. Likewise, the risk of toxicity is a major problem with currently available phototherapies and systemic treatments. Advances in understanding the aetiology and pathogenesis of psoriasis allude to the possibility of innovative, targeted therapies in the future.

Interventions for guttate psoriasis

BACKGROUND

Guttate psoriasis is a distinctive acute form of psoriasis which characteristically occurs in children and young adults. Very little specific evidence-based guidance is available in standard texts to help make rational decisions about treatment options.

OBJECTIVES

To assess the effectiveness of treatments for guttate psoriasis.

SEARCH STRATEGY

We searched the Cochrane Clinical Trials Register (Cochrane Library, Issue 3, 1999), Medline (1966- September 1999), Embase (1988-September 1999), Salford Database of Psoriasis Trials (to November 1999) and European Dermato-Epidemiology Network (EDEN) Psoriasis Trials Database (to November 1999) for terms GUTTATE and PSORIASIS. We also searched 100 unselected RCTs of psoriasis therapy and all 112 RCTs of phototherapy for psoriasis in the Salford Database of Psoriasis Trials for separate stratification for guttate psoriasis.

SELECTION CRITERIA

Randomised trials in which patients with acute guttate psoriasis were randomised to different treatments, except those trials examining antistreptococcal interventions which are addressed in a separate Cochrane review.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality.

MAIN RESULTS

No published report could be found to support or to challenge current commonly used methods of management. Only one trial which met the selection criteria was identified. In this small study of 21 hospitalised patients with guttate psoriasis, intravenous infusion of an n-3 fatty acid rich lipid emulsion was compared with placebo emulsion containing n-6 fatty acids. The n-3 preparation appeared to be of some benefit for patients with guttate psoriasis.

REVIEWER'S CONCLUSIONS

There is currently no firm evidence on which to base treatment of acute guttate psoriasis. Studies comparing standard treatment modalities, including phototherapy and topical regimens, are required to enable informed decisions on treatment choices to be made.

Antistreptococcal interventions for guttate and chronic plaque psoriasis

BACKGROUND

Guttate psoriasis is a distinctive acute form of psoriasis which characteristically occurs in children and young adults. It is closely associated with preceding streptococcal sore throat or tonsillitis. Some authorities have claimed that ordinary (chronic plaque) psoriasis may also be made worse by infection at distant sites. Although many dermatologists have recommended using antibiotics for guttate psoriasis in particular, it is not clear whether they influence the course of either form of psoriasis. Some dermatologists have also recommended tonsillectomy for psoriasis in patients with recurrent streptococcal sore throat.

OBJECTIVES

To assess the evidence for effectiveness of antistreptococcal interventions including antibiotics and tonsillectomy in the management of acute guttate and chronic plaque psoriasis.

SEARCH STRATEGY

We searched the Cochrane Clinical Trials Register (Cochrane Library, Issue 3, 1999), Medline (1966- September 1999), Embase (1988-September 1999), the Salford Database of Psoriasis Trials (to November 1999) and the European Dermato-Epidemiology Network (EDEN) Psoriasis Trials Database (to November 1999) for terms [STREPTOCOCC* or ANTIBIOTIC* or TONSIL*] and PSORIASIS using the Cochrane Skin Group search strategy.

SELECTION CRITERIA

Randomised trials of one or more antistreptococcal interventions in patients with guttate or chronic plaque psoriasis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently examined each retrieved trial for eligibility and quality.

MAIN RESULTS

The one eligible trial we identified compared the use of two oral antibiotic schedules in 20 psoriasis patients, predominantly of guttate type, who had evidence of beta-haemolytic streptococcal colonisation. Either rifampicin or placebo was added to the end of a standard course of antistreptococcal antibiotic (phenoxymethylpenicillin or erythromycin). No patient in either arm of the study improved during the observation period. No randomised trials of tonsillectomy for psoriasis were identified.

REVIEWER'S CONCLUSIONS

Although it is well known that guttate psoriasis may be precipitated by streptococcal infection, there is no firm evidence to support the use of antibiotics either in the management of established guttate psoriasis or in preventing the development of guttate psoriasis following streptococcal sore throat. Although both antibiotics and tonsillectomy have frequently been advocated for patients with recurrent guttate psoriasis or chronic plaque psoriasis, there is to date no good evidence that either intervention is beneficial.

Levels of endothelial cell stimulating angiogenesis factor and vascular endothelial growth factor are elevated in psoriasis

Neovascularization appears to play an early and important part in the evolution of psoriatic plaques. We studied the distribution and production of two known angiogenesis factors, endothelial cell stimulating angiogenesis factor (ESAF) and vascular endothelial growth factor (VEGF), in the skin of patients with chronic plaque psoriasis and normal control subjects. Our results showed that tissue levels of ESAF and VEGF were significantly elevated in involved as compared with normal control skin (P = 0.006 and P < 0. 0001, respectively). Tissue levels of ESAF and VEGF were also raised in involved skin as compared with uninvolved skin in patients with psoriasis (P = 0.001 and P < 0.0001, respectively). Tissue levels of ESAF and VEGF in plaques of psoriasis correlated closely with the clinical severity of psoriasis (r = 0.6 and r = 0.9, respectively). Serum levels of ESAF and VEGF were significantly raised in patients with psoriasis as compared with control subjects (P = 0.001 and P = 0.02, respectively). In vitro culture studies revealed that ESAF is produced by both keratinocytes and fibroblasts in approximately equal quantities in normal skin, whereas VEGF is secreted predominately by keratinocytes. A similar pattern is seen in both involved and uninvolved skin of patients with psoriasis. However, there is increased secretion of both factors in keratinocytes and fibroblasts from involved and uninvolved skin as compared with normal control skin (P < 0.001). The increased levels and secretion in plaques of psoriasis of two molecules, ESAF and VEGF, known to promote new blood vessel formation, suggest a pathogenetic role for them in this disease.

Figurate erythema with bullous pemphigoid: a true paraneoplastic phenomenon?

There has been controversy about the possible link between bullous pemphigoid and underlying malignancy. We report a case of bullous pemphigoid with marked figurate erythema which arose shortly before the clinical presentation of colonic carcinoma and cleared completely 1 week after its resection. We review the literature and conclude that patients who present with clinically atypical bullous pemphigoid may warrant investigation for underlying neoplasia.

Patients with psoriasis and their compliance with medication

BACKGROUND

Poor compliance with treatment advice in chronic conditions, such as psoriasis, represents a major challenge to health care professionals. Previous research suggests that the rate of noncompliance in chronic conditions may be as high as 40%.

OBJECTIVE

This study was designed to examine self-reported compliance in patients with psoriasis.

METHODS

We undertook an anonymous postal survey sent to consecutive patients with psoriasis attending a tertiary psoriasis specialty clinic.

RESULTS

Thirty-nine percent of participants reported that they did not comply with the treatment regimen recommended. The noncompliant group had a higher self-rated severity of psoriasis (t = -2.16, P =. 03), were younger (t = 3.28, P =.001), and had a younger age at onset (t = 2.35, P =.02) than those who were compliant. The noncompliant group reported that psoriasis had a greater impact on daily life (t = -2.23, P =.028), but general well-being was not significantly different from those who complied (t =.47, P = not significant).

CONCLUSION

Patients who reported intentional noncompliance with treatment advice were more likely to believe that both psoriasis and its treatment interfered with their quality of life but not overall well-being. The impact of treatment on daily life highlights the importance of joint decision making in planning treatment.

Chronic granulomatous disease and acute neutrophilic dermatosis

Chronic granulomatous disease is an inherited disorder characterized by defective oxidative killing by neutrophils and other phagocytes. This results in susceptibility to persistent and life-threatening infections. We describe a 25-year-old man with chronic granulomatous disease who presented with an acute, febrile neutrophilic dermatosis. This indicates that normal neutrophil intracellular killing mechanisms are not essential in the pathogenesis of neutrophilic dermatoses.

Intermittent short courses of cyclosporin (Neoral(R)) for psoriasis unresponsive to topical therapy: a 1-year multicentre, randomized study. The PISCES Study Group

We performed a 1-year study to determine whether intermittent short courses of the microemulsion formulation of cyclosporin (Neoral) could effectively control plaque psoriasis and whether tapering or abrupt cessation of cyclosporin therapy would influence time to relapse. Four hundred patients with plaque psoriasis were included in this open, multicentre, randomized study. All patients commenced cyclosporin at a dose of 2.5 mg/kg daily. Cyclosporin dosage could be increased to a maximum of 5 mg/kg daily. Treatment was continued until clearance of psoriasis or for a maximum of 12 weeks. Patients were then randomly assigned either to stop cyclosporin abruptly or to have the dose reduced by 1 mg/kg daily each week until cessation. On relapse, patients were given another course of cyclosporin. Patients were followed for at least 1 year, during which they could receive as many treatment courses as necessary. The number of patients who required one, two, three and four treatment courses was 400, 259, 117 and 26, respectively. The median time to relapse after the end of the first treatment period was 109 days in the group of patients randomized to stop cyclosporin abruptly and 113 days in patients randomized to taper off cyclosporin (P = 0.038). More than 30% of patients had not relapsed 6 months after having stopped treatment. After each treatment course, the Kaplan-Meier probability of achieving 75% or more reduction in disease area by day 84 of treatment was 83%, 76%, 73% and 66%, respectively. Mean serum creatinine concentration and blood pressure did not show any clinically significant changes over time. Our results show that intermittent short-course therapy with Neoral, when used in conjunction with topical therapy, is well tolerated and provides effective control of plaque psoriasis for 1 year. Tapering off cyclosporin on treatment cessation induces a slight delay in psoriasis relapse.

Tumour necrosis factor-alpha induces Langerhans cell migration in humans

The role of tumour necrosis factor (TNF)-alpha in the mobilization and migration of human epidermal Langerhans cells (LC) has been investigated. Intradermal injection of normal human volunteers with homologous recombinant TNF-alpha was found to cause a dose-dependent reduction in the frequency of LC within epidermal sheets 2 h later. Equivalent results were obtained when epidermal LC were identified on the basis of either CD1a or HLA-DR expression. At the dose of TNF-alpha used routinely (500 U), treatment resulted in an average reduction in LC density of approximately 24%. Treatment with TNF-alpha was associated with a perivascular polymorphonuclear infiltration at 2 h, but the epidermis appeared normal with neither fibrinoid necrosis nor vasculitis, and LC morphology was not affected significantly. These results demonstrate that TNF-alpha provides an important signal for LC migration in humans and is likely therefore to play a crucial part in the induction of cutaneous immune responses.

Clinical measures of disease severity and outcome in psoriasis: a critical appraisal of their quality

In clinical trials, a wide range of outcome measures has been used to evaluate the severity of psoriasis and its response to treatment. Despite their widespread use, many measures have received little attention with regards to their reliability and validity. Selecting an appropriately developed measurement tool is therefore of critical importance. We conducted a literature survey to examine the status of clinical outcome measures used in psoriasis research. The measures most commonly used were individual sign scores, e.g. for erythema, plaque thickness or scaling, and pooled indices, e.g. the Psoriasis Area and Severity Index. None of these, however, systematically fulfilled all the requirements of a validated instrument for disease assessment. Ideally, a core set of reliable and validated outcome measures for use in all psoriasis clinical trials is needed. Objective instrumental methods should minimise observer variation, but unless a simple non-invasive method can be developed, the uptake of such technology will probably be limited by cost and lack of practicality. Moreover, the translation of instrumental readings into clinically relevant measures is always a major problem, and for none of the methods has there been a robust mapping of instrumental readings on to a clinically meaningful scale. Further research is needed to determine the most appropriate and sensitive parameters to use as surrogate measures for capturing the distress which psoriatic patients feel but which is not measured with sufficient sensitivity or precision with current quality of life or distress questionnaires.

Combination treatment with methotrexate and cyclosporin for severe recalcitrant psoriasis

An increasingly important approach to the management of patients with severe psoriasis is the concurrent use of two systemic treatments. Previous guidelines have advised against the use of methotrexate and cyclosporin in combination. We report the successful use of a combination of methotrexate and cyclosporin in the treatment of 19 patients with severe, recalcitrant psoriasis, 15 of whom had psoriatic arthropathy. Most patients had previously received two or more systemic treatments. Before combination treatment was started nine of the patients were taking methotrexate and 10 were taking cyclosporin at the maximum tolerated doses. The duration of combination treatment was bimodally distributed, with seven patients having short-term treatment (mean +/- SD duration 18. 9 +/- 15.7 weeks) and 12 patients having long-term treatment (mean +/- SD duration 193.2 +/- 160.6 weeks). Those patients who received short-term treatment did not develop any evidence of toxicity from either agent. Of those patients on long-term treatment, three developed mild impairment of renal function that returned to normal following a reduction in dose of cyclosporin, and three had impairment of renal function (following long-term cyclosporin monotherapy) that improved, but did not normalize, following a reduction in dose of cyclosporin. In each case, combination treatment for psoriasis resulted in good control of both skin and joint problems using lower doses of each agent than would have been used for monotherapy. We conclude that the combination of methotrexate and cyclosporin is an effective treatment for this group of patients.

Dowling Oration delivered at the Royal College of Physicians, London, Friday 5 June 1998. Retinoids: renaissance and reformation

There is confusion as to the cutaneous signs of ageing. For the most part the features of photoageing, namely actinic lentigines and wrinkling, are misinterpreted as features of ageing. Wrinkling is associated with a loss of collagens from the papillary dermis resulting from imperfect remodelling of the dermal extracellular matrix following sun exposure. Retinoids are either derivatives of vitamin A or synthetic ligands of nuclear retinoid receptors. Retinoid receptors, notably retinoic acid receptor gamma and retinoid X receptor alpha are present in human skin. Topically applied all-trans retinoic acid can repair and probably prevent photoageing of the skin by modulation of collagen synthesis in the dermis. There is emerging evidence that intrinsic ageing of the skin is also amenable to reversal by topical retinoids.

Fibrillin-rich microfibrils are reduced in photoaged skin. Distribution at the dermal-epidermal junction

Chronic sun exposure results in photoaged skin with deep coarse wrinkles and loss of elasticity. We have examined the distribution and abundance of fibrillin-rich microfibrils, key structural components of the elastic fiber network, in photoaged and photoprotected skin. Punch biopsies taken from photoaged forearm and from photoprotected hip and upper inner arm of 16 subjects with a clinical range of photoaging were examined for fibrillin-1 and fibrillin-2 expression and microfibril distribution. In situ hybridization revealed decreased fibrillin-1 mRNA but unchanged fibrillin-2 mRNA levels in severely photoaged forearm biopsies relative to photoprotected dermal sites. An immunohistochemical approach demonstrated that microfibrils at the dermal-epidermal junction were significantly reduced in moderate to severely photoaged forearm skin. Confocal microscopy revealed that the papillary dermal microfibrillar network was truncated and depleted in photoaged skin. These studies highlight that the fibrillin-rich microfibrillar network associated with the upper dermis undergoes extensive remodeling following solar irradiation. These changes may contribute to the clinical features of photoaging, such as wrinkle formation and loss of elasticity.

Drug treatment of photoaged skin

Although the prevention of skin aging is a holy grail of the cosmetic and pharmaceutical industries, this venture may be misplaced. The predominant clinical and biochemical features of aged skin are mostly attributable to photoaging rather than chronology. For instance chronic sun exposure is the major determinant of age spots (actinic lentigines) and wrinkles. Surgical approaches to the treatment of photoaging include face-lift, dermabrasion, chemical peeling, collagen and botulinum toxin injections, and laser re-surfacing. These approaches all have benefit and improve the clinical features of facial photoaging. Drug or pharmaceutical prevention and treatment of photoaged skin is still in its infancy. The main pharmaceutical approach to prevention of photoaging lies in the assiduous use of sunscreens. Recent evidence points to the importance of ultraviolet A (UVA) radiation as well as ultraviolet B (UVB) radiation in the aetiology of photoaging and thus the need for sunscreens that block both UVB and UVA. Drug treatment of photoaged skin can be categorised as antioxidants, alpha-hydroxy acids and topical retinoids. Of these 3 approaches only topical retinoids, particularly tretinoin (all-trans retinoic acid), have a well documented ability to repair photoaged skin at the clinical, histological and molecular level. Furthermore, the use of topical retinoids may actually prevent photoaging. The current interest in pharmaceutical modulation of the photoaging process has attracted considerable research into the mechanisms of photoaging and cutaneous aging. It is likely that treatment for, or prevention of, the chronological aging process may result from such research.