Nail clippings from patients with psoriasis present abnormally thickened subungual region with prominent hypercorneocytosis, serous lakes, bacteria, neutrophils, and blood collections. If fungi are present, usually there are spores. Clinically, normal-looking nails in patients with psoriasis can present microscopic abnormalities.

Erosive pustular dermatosis of the scalp is a rare inflammatory disorder of the scalp, affecting elderly patients after local trauma and leading to scarring or cicatricial alopecia. Case Report: An elderly female patient complained of painful pustules on the parietal region bilaterally with progressive enlargement and ulceration. A biopsy suggested erosive pustular dermatosis of the scalp and the patient was treated with prednisone 40 mg/day and 0.1% topical tacrolimus. After 10 weeks complete closure of the eroded areas was observed and a stable scarring alopecia developed.

BACKGROUNDThe nail involvement in psoriasis is related to psoriatic arthritis and may represent a predictor of the disease.OBJECTIVESTo analyze, through nail clipping, clinically normal and dystrophic nails of patients with cutaneous psoriasis and psoriatic arthritis.METHODSThis is a cross-sectional multicenter study, conducted between August 2011 and March 2012. Patients were divided into four groups: patients with cutaneous psoriasis and onychodystrophy, patients with cutaneous psoriasis and clinically normal nails, patients with psoriatic arthritis and onychodystrophy and patients with psoriatic arthritis and clinically normal nails. We calculated NAPSI (Nail Psoriasis Severity Index) of the nail with more clinically noticeable change. After collection and preparation of the nail clipping, the following microscopic parameters were evaluated: thickness of the nail plate and subungual region, presence or absence of parakeratosis, serous lakes, blood, and fungi.RESULTSThere were more layers of parakeratosis (p=0.001) and a greater thickness of the subungual region in patients with cutaneous psoriasis and onychodystrophy (p=0.002). Serous lakes were also more present in the same group (p=0.008) and in patients with psoriatic arthritis and normal nails (p=0.047). The other microscopic parameters showed no significant difference between normal and dystrophic nails or between patients with psoriatic arthritis or cutaneous psoriasis.STUDY LIMITATIONSSmall sample size and use of medications.CONCLUSIONSNail clipping is a simple and quick method to assess the nails of patients with nail psoriasis although does not demonstrate difference between those with joint changes or exclusively cutaneous psoriasis.

WHICH IS YOUR DIAGNOSIS? HISTORY OF THE DISEASEMale patient, seven-years-old, with a history of discrete pruriginous skin lesions for 18 months. Lesions first appeared on his forearms and rapidly disseminated. The patient denied the use of previous medication, comorbidities or familial history of skin lesions. Physical examination revealed small, nonscaly, smooth and shiny skin-colored papules, with 1-2 mm of diameter, affecting nearly all his skin, sparing only nails, palmoplantar regions, mucous membranes, and part of his hair scalp (Figures 1, 2).Histopathological evaluation showed the presence of dense lymphohistiocytic dermal infiltrate, partially surrounded by interpapillary cones, atrophic superadjacent epidermis, and parakeratosis (Figures 3 and 4). Culture was negative for acid-fast bacilli (BAAR) and fungi.