MART-1 is a reliable melanocytic marker in lichen planus-like keratosis: a study on 70 cases.

Recent studies have proposed that MART-1 may falsely stain clusters of intraepidermal nonmelanocytic cells in lichenoid dermatitides. This may become an issue especially in isolated lesions of lichen planus-like keratosis (LPLK), a condition also known as benign lichenoid keratosis, and one that is often mistaken clinically for a malignant cutaneous neoplasm. LPLKs are known to exhibit basal epidermal pseudonests, mimicking a regressing melanocytic lesion histologically, and often may prompt the pathologist to obtain a MART-1 stain. If MART-1 is falsely positive, it may seal an incorrect diagnosis. To determine whether or not pseudonests in LPLK decorated with MART-1, we reviewed 70 cases from our institution, stained them with MART-1 (Thermo Fisher-Lab Vision, Ab3 clone, 1:400 dilution, heat-induced epitope retrieval with 0.02M citrate buffer at pH 6.0), and evaluated them for the presence or absence of staining within pseudonests. Four cases demonstrated an occasional MART-1-positive junctional nest. In these cases, microphthalmia transcription factor was also positive, confirming a true melanocytic origin. None of the other cases showed a MART-1 pattern that would have been suspicious for a melanocytic lesion. We propose that this discrepancy between our study and prior ones may be explained by differences in staining protocols or by a very low incidence of non-specific staining. Our study suggests that MART-1 is a useful marker in differentiating melanocytic nests from pseudonests in LPLK.

The evolution of histopathologic findings in adult Still disease.

Adult Still disease is an inflammatory arthritis classically associated with daily spiking fevers, evanescent rash, organomegaly, lymphadenopathy, and laboratory anomalies. The typical cutaneous lesions are thin pink papules in a morbilliform distribution, of short duration. Histologically, these lesions are characterized by a superficial perivascular and interstitial mixed dermatitis with lymphocytes and variable neutrophils. A variant clinical presentation is increasingly recognized, which demonstrates persistent hyperpigmented plaques, often with a rippled or linear appearance. The histologic findings consist of upper epidermal dyskeratotic keratinocytes, increased dermal mucin, and a superficial perivascular infiltrate of lymphocytes and possibly neutrophils or eosinophils. We encountered 2 patients who presented with the characteristic rash of adult Still disease, both of whom progressed to develop the pigmented cutaneous plaques. We propose that this variant clinical and histologic appearance is the outcome of persistent disease activity.

Effects of a novel formulation of fluocinonide 0.1% cream on skin barrier function in atopic dermatitis.

OBJECTIVE: To determine the effect a novel formulation of fluocinonide cream on skin barrier function in subjects with atopic dermatitis. DESIGN: The authors performed an open-label, investigator-blinded, side-by-side, controlled trial examining skin barrier function before and after a two-week course of a class I, super-potent topical steroid. SETTING: Outpatient university-based dermatology clinic in Portland, OR. SUBJECTS: Twenty-five subjects aged 12 or older with a diagnosis of moderate, severe, or very severe AD were recruited for this study. INTERVENTION: Fluocinonide 0.1% cream, a novel formulation of a class I super-potent topical steroid was applied to all affected areas, except a control site, once daily for two weeks or until clear. The control target site was treated with the vehicle once daily. MAIN OUTCOME MEASURE(S): The study's primary outcome was change in skin barrier function as measured by basal transepidermal water loss (TEWL) in acute lesional skin from baseline as measured at two weeks. RESULTS: TEWL readings significantly decreased (reflecting improved barrier function) in both the active and control target sites. The active target site decreased 14.35+/-16 mg/cm2 per hour; 95 percent confidence interval, P<0.001. The control target site decreased 8.75+/-11.80 mg/cm2 per hour in 25 subjects; 95 percent confidence interval, P<0.001. Skin electrical capacitance also improved significantly, reflecting improved stratum corneum hydration with therapy. Pruritus, clinical severity, and quality of life scores all showed significant improvement by the end of the study. CONCLUSION: The authors have shown that short-term treatment with a novel formulation of 0.1% fluocinonide led to significantly improved barrier function as measured by basal TEWL in subjects with active moderate to severe AD. These data suggest short-term treatment with AD with a super-potent corticosteroid improves skin barrier function.