Subcorneal pustular dermatosis (SCPD, also known as Sneddon-Wilkinson disease) is a rare, benign, chronic, sterile pustular eruption which usually develops in middle-age or elderly women; it is rarely seen in childhood and adolescence. The primary lesions are pea-sized pustules classically described as half-pustular, half-clear flaccid blisters. Histologically the most important feature is a subcorneal accumulation of neutrophils with the absence of spongiosis or acantholysis, although acantholysis may be reported in older lesions. In this paper we present the case of a 7-year-old boy diagnosed with SCPD based on the characteristic clinical and histological features. Dapsone has been successfully used in the treatment of the disease.
Subcorneal pustular dermatosis (SCPD, Sneddon-Wilkinson disease) is a rare chronic, relapsing, pustular eruption that was first described by Sneddon and Wilkinson in [
Its exact pathophysiology is unknown and its exact nosological classification is still controversial. The salient histological feature is a subcorneal accumulation of neutrophils with the absence of spongiosis or acantholysis.
Therapeutically, Dapsone is the first-line treatment in SPD [
A 7-year-old boy was admitted to our clinic with a 3-week-old itchy eruption located on the trunk, on the limbs, and on the face. He had a history of atopic dermatitis, while his familiar anamnesis was negligible. A complete blood count and the studies of serum biochemistry showed normal results; moreover serum protein electrophoresis had negative results. The lesions initially developed on the trunk and upper extremities, then they progressed up to involve almost the whole body surface. The palms, soles, and mucous membrane were spared, and no lymphadenopathy or hepato-splenomegaly was present. There were no abnormalities of the nails and tongue.
The dermatologic examination revealed multiple-grouped flaccid pustules varying in size from 2 to 10 mm that tended to coalesce to form annular, circinate, or serpiginous pattern and superficial crusts on the normal or mildly erythematous skin, of the face, trunk, and extremities (Figure
Multiple-grouped flaccid pustules varying in size from 2 to 10 mm that tended to coalesce to form annular, circinate, or serpiginous pattern and superficial crusts on the normal or mildly erythematous skin, of the face, trunk, and extremities.
Taking into consideration a suspected diagnosis of SCPD, the patient was treated with oral antihistamines and with a topic solution of eosin (2%); moreover an incisional biopsy of a lesion on the sternal region was carried out.
Histopathology demonstrated a subcorneal vesiculo-bullous dermatitis (Figure
Histological examination: subcorneal pustule immediately below the stratum corneum containing mainly neutrophils; the underlying epidermis show slight intercellular edema (HE
Immunofluorescence. IgA-FITC 40X. The figure shows no antibody reactivity in epithelial cells and dermal-epithelial junction (basement membrane).
The patient was treated with 30 mg of oral Diaminodiphenylsulfone (Dapsone, 1 mg/kg/day). The cutaneous lesions were almost completely healed at the first followup, within 2 weeks (Figure
Followup at 2 weeks. The patient was treated with Dapsone. The cutaneous lesions were almost completely healed.
After 3 months, the patient is still monitored for the followup at our hospital every 2 weeks.
Children can have various bullous and pustular skin diseases like pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, pustular bacterid, and psoriasis as well as dermatitis herpetiformis [
The etiology of the disease is still obscure. There are well-documented SCPD in associations with benign monoclonal IgA gammopathy [
In our case, the history, physical examination, and laboratory results did not reveal any systemic associations. Moreover some cases, which were consistent with SCPD according to the clinical and histologic features, have been reported with the presence of an intercellular IgA deposition within the epidermis [
This disease involves more frequently the trunk, intertriginous areas, and flexor aspects of the limbs; more rarely the face is implicated, as in this case. Pustules on palms and soles have also been reported [
The differential diagnosis of SCPD includes pustular psoriasis, impetigo, dermatophyte infection, and immunobullous diseases (dermatitis herpetiformis, pemphigus, linear IgA disease, and intercellular IgA diseases). Unlike pustular psoriasis, nails and scalp are uncommonly affected in SCPD; moreover spongiform pustules, formation of microabscess, and elongation of rete ridges do not occur in classical Sneddon-Wilkinson disease [
In the IgA pemphigus subtype, generally, the acantholysis tends to be more pronounced than in SCPD, Sneddon-Wilkinson disease, in this regard, in our sample, were not observed acantholytic cells; moreover, in the IgA pemphigus, DIF studies demonstrate intercellular IgA accumulation in squamous cells.
In Sneddon and Wilkinson's original report [
Only 15 cases of pediatric SCPD are described in literature [
Sarkany [
R. E. Burns, MD, had a patient with subcorneal pustular dermatosis who gave birth to a child with similar skin lesions that lasted seven days (oral communication, April 1973) [
Desmons and Defrenne [
Johnson and Cripps [
Garg et al. [
In 1986 Rosińska-Borkowska and Henig published a case report about a 30-month-old patient with SCPD [
In 2003 Koçak et al. [
The last case reported in literature shows a case of juvenile subcorneal pustular dermatosis successfully treated with acitretin [
Even if SCPD is an uncommon condition in childhood, it must be considered as a possible cause of sterile pustular eruptions in a child. An accurate physical examination, a complete blood count, and studies of serum biochemistry are strongly recommended to exclude a pathology in association. Dapsone remains the treatment of choice but its safe is still debatable and a close followup is required.
The authors declared that they have no conflict of interests.