[Circumscribed palmar hypokeratosis (CPM): The diagnostic value of dermoscopy]. / Hypokératose acrale circonscrite (HAC) : utilité diagnostique de la dermoscopie.

BACKGROUND: Circumscribed palmar hypokeratosis (CPH) is a rare skin disease, first described in 2002, associated with sudden localized reduction of the corneal layer. In most cases, it presents as an isolated rounded erythematous palmar lesion on the thenar eminence. We describe the dermoscopic semiology of CPH in 3 cases. PATIENTS AND METHODS: Three patients between the ages of 59 and 72 presented very limited erythematous lesions suggestive of CPH. Dermoscopic examination of these lesions provided similar findings. Biopsy, which was performed in one patient, confirmed the diagnosis of CPH. RESULTS: Two dermoscopic elements of CPH are characteristic: (1) the sides of the lesion have a "stair step" or "geological strata" type of configuration, and the thickness of the different strata varies; (2) the centre of the lesion showed a homogeneous erythematous area with a vascular pattern composed of dotted vessels of the superficial dermis and sometime vascular loops. DISCUSSION: These dermoscopic aspects are characteristic and enable CPH to be differentiated from Bowen's disease or porokeratosis of Mibelli. In Bowen's disease, there is no stair step like aspect to the sides of lesions; further, the centre of the lesion shows glomerular vessels (coiled vessels) and/or globular vessels (small red clods). In porokeratosis, peripheral keratotic "white track" structures comprise a single pigmented channel or a double white line. There is no "stair step" or central vascular pattern. CONCLUSION: The dermoscopic semiology of CPH is highly characteristic and enables differentiation from Bowen's disease and porokeratosis.

[Metameric macular and papular skin mastocytosis]. / Mastocytose cutanée maculopapuleuse métamérique.

BACKGROUND: Mastocytosis is characterised by the presence of abnormal quantities of mastocytes in one or more organs. Although it occurs in systemic forms of mastocytosis, isolated skin involvement is the predominant presentation, particularly in children, in the form of more or less extensive though non-systematic lesions. Herein, we report a case of maculopapular cutaneous mastocytosis that is unusual in terms of its metameric topography. PATIENTS AND METHODS: A 16-year-old youth presented with an erythematous maculopapular rash of 18 months' duration and involving pruritic inflammatory episodes strictly localised in segment T8 to the left. The skin biopsy showed a significant increase in the number of dermal mastocytes (CD117+). No KIT mutations were found in the skin lesions nor in the unimpaired skin of the opposite side. Further investigations ruled out systemic mastocytis. DISCUSSION: Herein, we report a case of cutaneous mastocytosis that is unusual in terms of its metameric disposition. There have been only two previous reports of segmental cutaneous mastocytis. The two pathological hypotheses involved precessional dermatitis that renders the skin surface susceptible to homing, and somatic mosaicism (type 1) with local mastocyte proliferation.

Safety and efficacy of calcipotriol plus betamethasone dipropionate gel in the treatment of scalp psoriasis in adolescents 12-17 years of age.

BACKGROUND: Plaque psoriasis has a relatively high prevalence in adolescence, resulting in a significant impact on quality of life, including social interactions. OBJECTIVES: The primary objective was to assess the safety of once-daily application of fixed-combination calcipotriol plus betamethasone dipropionate gel in adolescent scalp psoriasis. Assessment of efficacy was a secondary objective. METHODS: This phase II, multicentre, single-arm, open-label, 8-week trial included patients aged 12-17 years with moderate-to-very severe scalp psoriasis according to Investigator's Global Assessment (IGA) (≥ 10% of the scalp area affected). RESULTS: Seventy-eight patients received treatment. Twenty-seven patients (35%) reported a total of 64 adverse events (AEs); most were mild (33/64) or moderate (22/64) in severity and there were no serious AEs. No cases of hypercalcaemia were reported, and the mean changes from baseline to end of treatment in albumin-corrected serum calcium (0·00 mmol L(-1)), 24-h urinary calcium excretion (-0·03 mmol per 24 h) and urinary calcium-to-creatinine ratio (-0·12 mmol g(-1)) were not considered clinically relevant. At the end of treatment 66 patients (85%) were clear or almost clear according to IGA. There was an 80% improvement in mean Total Sign Score from baseline to end of treatment. In total, at the end of treatment, 87% of patients rated their scalp psoriasis as clear or very mild, and 75 (96%) had no or mild pruritus compared with 14 (18%) at baseline. CONCLUSIONS: Once-daily calcipotriol plus betamethasone dipropionate gel is well tolerated and efficacious for scalp psoriasis in adolescents.