Bioactive substances in the stratum corneum of the epidermis found as indicators of skin damage due to sun exposure.

BACKGROUND/PURPOSE: Although an inflammatory response upon acute injury caused by ultraviolet radiation (UV) can be observed immediately, the influence of long-term, repetitive low-dose UV exposure on the skin cannot be precisely perceived, making early detection of chronic damage difficult. This study investigated bioactive substances in the stratum corneum as a potential early and sensitive indicator of the influence of sun exposure on the skin using receiver operating characteristic (ROC) analysis. METHODS: Receiver operating characteristic analysis was performed to assess the responsiveness of cytokines [interleukin (IL)-1α, IL-1 receptor antagonist (IL-1ra), IL-10, tumor necrosis factor (TNF)-α], BCL2-associated protein X (Bax), Toll-like receptor (TLR)3, and TLR4 in the stratum corneum of healthy people exposed (dorsum of the hand) and unexposed (inner arm) to UV. Sunscreen was applied to patients with photodermatosis for 4 weeks to evaluate changes in IL-1ra/IL-1α, TNF-α, Bax, and TLR3 levels after sunscreen application, as these molecules exhibited high responsiveness to sun exposure according to ROC analysis. In addition, IL-1ra, IL-1α, and IL-10 levels were quantified by enzyme-linked immunosorbent assay, and TNF-α, Bax, TLR3, and TLR4 levels were semi-quantitatively assessed by immunocytochemistry. RESULTS: Receiver operating characteristic analysis identified IL-1ra/IL-1α, TNF-α, Bax, and TLR3 in the stratum corneum as highly responsive to sun exposure. Moreover, in participants, including patients with photodermatosis, IL-1ra/IL-1α, TNF-α, and Bax levels decreased significantly after sunscreen application. CONCLUSION: The results revealed that IL-1ra/IL-1α, TNF-α, and Bax in the stratum corneum represent sensitive indicators of the influence of sun exposure on the skin.

A randomized, open-label, multicenter trial of topical tacrolimus for the treatment of pruritis in patients with atopic dermatitis.

BACKGROUND: Pruritis caused by atopic dermatitis (AD) is not always well controlled by topical corticosteroid therapy, but use of tacrolimus often helps to soothe such intractable pruritis in clinical settings. OBJECTIVE: To determine the anti-pruritic efficacy of topical tacrolimus in treating AD in induction and maintenance therapy. METHODS: Prior to the study, patients were randomly allocated into two groups, induction therapy followed by tacrolimus monotherapy maintenance, and induction therapy followed by emollient-only maintenance. In the induction therapy, the patients were allowed to use topical tacrolimus and emollients in addition to a low dose (<10 g/week) of topical steroids. Patients showing relief from pruritis were allowed to proceed to maintenance therapy. Recurrence of pruritis in maintenance therapy was examined as a major endpoint. RESULTS: Two-thirds of patients (44/68; 64.7%) showed relief from pruritis after induction therapy. Pruritis recurred in 23.8% (5/21) of the tacrolimus monotherapy group and in 100% (21/21) of the emollient group during maintenance period, a difference that was statistically significant. CONCLUSION: Use of topical tacrolimus is effective in controlling pruritis of AD compared to emollient.

Guidelines for management of atopic dermatitis.

Atopic dermatitis (AD) is a chronic relapsing eczematous skin disease characterized by pruritus and inflammation and accompanied by cutaneous physiological dysfunction (dry and barrier-disrupted skin). Most of the patients have atopic diathesis. A standard guideline for the management (diagnosis, severity classification and therapy) of AD has been established. In our guideline, the necessity of dermatological training is emphasized in order to assure diagnostic skill and to enable evaluation of the severity of AD. The definitive diagnosis of AD requires the presence of all three features: (i) pruritus; (ii) typical morphology and distribution; and (iii) chronic and chronically relapsing course. For the severity classification of AD, three elements of eruption (erythema/acute papules, exudation/crusts and chronic papules/nodules/lichenification) are evaluated in the most severely affected part of each of the five body regions (head/neck, anterior trunk, posterior trunk, upper limbs and lower limbs). The areas of eruption on the five body regions are also evaluated, and both scores are totaled (maximum 60 points). The present standard therapies for AD consist of the use of topical corticosteroids and tacrolimus ointment as the main treatment for the inflammation, topical application of emollients to treat the cutaneous physiological dysfunction, systemic antihistamines and anti-allergic drugs as adjunctive treatments for pruritus, avoidance of apparent exacerbating factors, psychological counseling and advice about daily life. Tacrolimus ointment (0.1%) and its low-density ointment (0.03%) are available for adult patients and 2-15-year-old patients, respectively. The importance of the correct selection of topical corticosteroids according to the severity of the eruption is also emphasized. Furthermore, deliberate use of oral cyclosporine for severe recalcitrant adult AD is referred.

Mutations in lipid transporter ABCA12 in harlequin ichthyosis and functional recovery by corrective gene transfer.

Harlequin ichthyosis (HI) is a devastating skin disorder with an unknown underlying cause. Abnormal keratinocyte lamellar granules (LGs) are a hallmark of HI skin. ABCA12 is a member of the ATP-binding cassette transporter family, and members of the ABCA subfamily are known to have closely related functions as lipid transporters. ABCA3 is involved in lipid secretion via LGs from alveolar type II cells, and missense mutations in ABCA12 have been reported to cause lamellar ichthyosis type 2, a milder form of ichthyosis. Therefore, we hypothesized that HI might be caused by mutations that lead to serious ABCA12 defects. We identify 5 distinct ABCA12 mutations, either in a compound heterozygous or homozygous state, in patients from 4 HI families. All the mutations resulted in truncation or deletion of highly conserved regions of ABCA12. Immunoelectron microscopy revealed that ABCA12 localized to LGs in normal epidermal keratinocytes. We confirmed that ABCA12 defects cause congested lipid secretion in cultured HI keratinocytes and succeeded in obtaining the recovery of LG lipid secretion after corrective gene transfer of ABCA12. We concluded that ABCA12 works as an epidermal keratinocyte lipid transporter and that defective ABCA12 results in a loss of the skin lipid barrier, leading to HI. Our findings not only allow DNA-based early prenatal diagnosis but also suggest the possibility of gene therapy for HI.

Linear scleroderma along Blaschko's lines in a patient with systematized morphea.

We have previously shown that frontoparietal scleroderma en coup de sabre, a type of linear scleroderma that affects the face and scalp, follows the lines of Blaschko, but the question whether linear scleroderma that occurs in the limbs follows Blaschko's lines has not been answered. We describe the case of a 4-year-old girl with multiple morphea showing remarkable unilateral systematized distribution and whose linear lesions in the limbs appeared to follow Blaschko's lines. We suggest that linear scleroderma of the limbs, as well as frontoparietal scleroderma, may occur along the lines of Blaschko. Since both the unilateral distribution and the lesions along Blaschko's lines are the patterns created by genetic mosaicism, we suggest that a significant part of linear scleroderma and perhaps a smaller part of multiple morphea could be related to cutaneous mosaicism.