As yet no transdermal topical formulations have been developed for the treatment of chronic itch. We developed a formulation containing 2 mg butorphanol tartrate in 100 microl purified water encapsulated into multilamellar phospholipid vesicles. Drug permeation experiments were studied with Franz diffusion chambers using human skin in vitro and on rat skin in vivo. Histological analysis of rat skins was performed to evaluate skin irritation of the formulation in vivo. Physical properties showed stable formulation with desirable viscosity. In vitro dermal penetration rate data suggest that there was significant permeation at time-points 2 h and 4 h, and a steady state was achieved afterwards to 24 h. Maximal plasma butorphanol concentration was noted at 2 h and steady state was achieved at 8 h. Visual skin assessment as well as histological analysis of excised rat skin did not demonstrate any evidence of inflammation and irritation. In vitro and in vivo analysis demonstrated release of a consistent amount of butorphanol in a sustained manner for 24 h. This liposomal transdermal delivery formulation could serve as a method to deliver butorphanol for patients with chronic pruritus.

Our understanding of the world around us is derived from our observations. The accuracy of our inferences depends on the representativeness of those observations. Selection bias limits the accuracy of our inferences. Systematic selection bias occurs when the particular outcome observed caused the observation; this type of bias can lead to dramatic errors in inference. We describe examples of selection bias, provide a mathematical formulation of the systematic selection bias phenomenon, and discuss how biased observations may affect people's impressions of important issues in dermatology.

Sebum production is thought to play a major role in acne vulgaris in adolescents. Psychological stress may exacerbate acne; however, it is not known whether the perceived association between stress and acne exacerbation is due to increased sebum production. The aims of this study were to determine: (i) if psychological stress in adolescents is associated with increased sebum production; and (ii) if stress is associated with increased acne severity independent of, or in conjunction with, increased sebum production. Ninety-four secondary school students in Singapore (mean age 14.9 years) were enrolled in this prospective cohort study. During a high stress condition (prior to mid-year examinations) and a low stress condition (during the summer holidays), the following were evaluated: (i) self-reported stress level using the Perceived Stress Scale; (ii) sebum level at baseline and at 1 h; and (iii) acne severity. The prevalence of self-reported acne in this study population was high (95% in males and 92% in females). Most subjects had mild to moderate acne. Sebum measurements did not differ significantly between the high stress and low stress conditions. For the study population as a whole, we observed a statistically significant positive correlation (r=0.23, p=0.029) between stress levels and severity of acne papulopustulosa. In adolescents, psychological stress does not appear to affect the quantity of sebum production. The study suggests a significant association between stress and severity of acne papulopustulosa, especially in males. Increased acne severity associated with stress may result from factors other than sebum quantity.

Background: Few large-scale epidemiological studies have been performed on the prevalence of itch. Itch and pain are common and complex symptoms which contribute to the burden of disease. Although there is antagonistic interaction between itch and pain, there are also many similarities in their pathophysiology. Objective: To investigate possible associations between chronic itch and chronic pain in a large population. Methods: The design was cross-sectional. 18,770 adults completed a self-administered questionnaire addressing sociodemographic factors, psychosocial factors and self-reported health including chronic itch and chronic pain. Results: Individuals reporting pain and itch were more likely to be women ( 80 and 60%, respectively, compared to 55% in the total sample), had a lower income ( 49 and 37% compared to 32%), were more likely to be depressed ( 36 and 20% compared to 11%) and reported poorer well-being ( 74 and 34% compared to 25%). In an adjusted logistic regression, chronic pain was strongly associated with chronic itch ( OR = 1.79, 95% CI = 1.43-2.24). Conclusion: This study demonstrates the association of chronic itch and chronic pain and points out the need of further studies that focus on both symptoms in dermatological diseases. Copyright (c) 2007 S. Karger AG, Basel

BACKGROUND:Controversy exists in the literature regarding the use of Mohs surgery for the treatment of melanoma in situ (MIS). Mohs surgery provides the advantage of complete margin assessment; however, variations in surgical and laboratory techniques employed, make comparison of outcomes difficult. OBJECTIVE:To review the current literature regarding Mohs surgery for treatment of MIS and to evaluate treatment options. METHODS:We review the literature regarding traditional excision margins for MIS, the proportion of biopsy-proven MIS lesions that prove to have an invasive component, and the efficacy of Mohs surgery for MIS. RESULTS:Many authors report a need for surgical margins larger than the recommended 5 mm, particularly with MIS arising in sun-exposed areas. Further, a review of the literature reveals that nearly one-quarter of biopsy-proven MIS lesions are found to contain invasive melanoma after complete surgical removal and pathologic examination. Substantial evidence supports the value of complete margin assessment in the treatment of MIS, particularly in the head and neck region. CONCLUSION:Complete surgical excision with careful margin assessment is required to adequately treat MIS lesions, particularly given the high rate of invasive melanoma in lesions initially thought to be MIS. Mohs surgery remains the treatment of choice for all clinically ill-defined MIS.

Psoriasis is one of the most common chronic skin diseases, and unprecedented increases in the elderly population will make diagnosis and management of geriatric psoriasis increasingly important. Management of psoriasis in the elderly requires consideration of several important factors. Many commonly prescribed drugs can precipitate psoriasis or aggravate pre-existing psoriasis. In addition, elderly patients are at increased risk of adverse drug reactions due to polypharmacy, adverse drug–drug interactions, adverse drug–disease interactions, incorrect use of medication and concomitant comorbidities. Psoriasis is a highly variable disease that requires individualized treatment. The major classes of topical medications include topical corticosteroids, coal tar preparations, calcipotriol, tazarotene and salicylic acid. Phototherapy, including narrowband ultraviolet B, photochemotherapy, psoralen ultraviolet A and excimer laser treatment, can be effective in properly selected patients. Systemic therapy for psoriasis in the elderly should be reserved for severe, extensive cases that have failed to respond to topical treatment, and may include methotrexate, systemic retinoids and immunotherapy.

Background: Several studies using nailfold capillary microscopes have demonstrated capillary changes in patients with dermatomyositis (DM); however, no previous study has examined cutaneous blood flow in this disease.Purpose: To determine cutaneous blood flow in involved and non-involved skin surfaces of patients with DM and to assess possible correlation with clinical measures of disease severity.Methods: Using a Laser Doppler perfusion imager, cutaneous blood flow was measured at six targeted sites of involved and apparently non-involved skin of 13 DM patients and the corresponding non-involved sites of 13 healthy controls. Overall disease severity of DM patients was determined by physician's global assessment (PGA), creatinine phosphokinase (CPK) levels, medical research council (MRC) scores, and the DM skin severity index (DSSI).Results: Skin blood flow was significantly elevated in involved vs. non-involved skin of DM patients at all anatomic sites measured: periungual (P=0.001), knuckle (P=0.001), elbow (P=0.013), periorbital (P=0.015), chest (P=0.028), and back (P=0.001). Blood flow was also higher in apparently non-involved skin of DM patients vs. skin of healthy controls at all anatomic sites, although statistical significance was not achieved. A significant negative correlation was observed between the DSSI and blood flow in involved skin of the chest (P=0.003), back (P=0.002), and knuckle (P=0.026).Conclusion: DM is associated with significantly increased cutaneous blood flow, even at sites where no erythema is evident. This suggests significant involvement of the skin vasculature in this disease process.

Obesity is widely recognized as an epidemic in the Western world; however, the impact of obesity on the skin has received minimal attention. The purpose of this article is to highlight the association between obesity and dermatologic conditions. We review the impact of obesity on the skin, including skin physiology, skin manifestations of obesity, and dermatologic diseases aggravated by obesity. Obesity is responsible for changes in skin barrier function, sebaceous glands and sebum production, sweat glands, lymphatics, collagen structure and function, wound healing, microcirculation and macrocirculation, and subcutaneous fat. Moreover, obesity is implicated in a wide spectrum of dermatologic diseases, including acanthosis nigricans, acrochordons, keratosis pilaris, hyperandrogenism and hirsutism, striae distensae, adiposis dolorosa, and fat redistribution, lymphedema, chronic venous insufficiency, plantar hyperkeratosis, cellulitis, skin infections, hidradenitis suppurativa, psoriasis, insulin resistance syndrome, and tophaceous gout. We review the clinical features, evidence for association with obesity, and management of these various dermatoses and highlight the profound impact of obesity in clinical dermatology.

BACKGROUND The relationship between dry skin and uraemic pruritus remains controversial. In addition, there is a lack of published data describing the structure and function of the stratum corneum (SC) in end-stage renal disease (ESRD). The purpose of the present study was to assess the function and structure of the skin barrier in patients with ESRD and to correlate any abnormalities with uraemic pruritus. METHODS Thirty-eight subjects participated in the study; 20 with ESRD and 18 healthy controls. Subjects underwent evaluation of SC integrity and permeability barrier recovery, SC surface pH, pruritus and dry skin. The content of glycerol, an important endogenous humectant, was assessed in D-squame tape strips from seven patients with ESRD. Skin biopsies from six of these patients were examined by electron microscopy using ruthenium tetroxide (Ru04)-post-fixation. RESULTS Although SC integrity was impaired in ESRD patients (P = 0.001), there were no significant differences in permeability barrier recovery rates between ESRD subjects and controls. However, there was a high significant negative correlation between SC glycerol content and dry skin in the arms of ESRD subjects (r = -0.866, P = 0.01). Yet, there was no consistent correlation between pruritus and either dry skin, SC integrity, glycerol content or surface pH. Electron microscopy revealed no significant ultra-structural abnormalities, with particular reference to the lipid bi-layer. CONCLUSIONS SC integrity, but not permeability barrier recovery, is impaired in dialysis patients. Although dry skin in ESRD is associated with reduced SC glycerol levels, the ultra-structure appears to be unaffected.

Itch is an important, but underestimated symptom in psoriasis. Many therapies are available for pruritus; however, few are effective for psoriatic itch. Antipruritic therapies that are potentially effective in psoriasis include coal tar products, topical corticosteroids, topical salicylates, menthol and pramoxine, capsaicin, phototherapy, vitamin D analogs, topical immunomodulators, methotrexate, oral mirtazapine, and biologics. Using these therapies can benefit psoriasis patients in the outpatient clinical setting.