Subcorneal Pustular Dermatosis (Sneddon and Wilkinson Disease)
Subcorneal pustular dermatosis (SPD) was described in 1956 by Ian Sneddon and Darrell Wilkinson (Sneddon & Wilkinson, 1956). SPD is less common than SS and PG.
SPD is characterized by a subacute or chronic aseptic intra-epidermal subcorneal unilocular pustular eruption that is not associated with identified auto-antibodies.
The eruption is made of pustules of variable size (from 2 to 10 mm). When pustules are large enough, a horizontal level between the aseptic pus (below) and the overlying secretion may be seen; this "hypopyon" is evocative of SPD. Typically, pustules are asymptomatic, have an arciform distribution and are surrounded by an annular erythema. Lesions tend to concentrate around large folds, namely axillae and groins (see Figure 3). SPD spontaneously evolve with an alternating of flares and remissions.
Figure 3.
Subcorneal pustular dermatosis
Skin histopathology shows subcorneal unilocular pustules. Direct skin immunofluorescence is negative (which assists in ruling out autoimmune blistering diseases). Bacterial and mycological work-up on a swabbing of freshly broken pustules is negative (which assists in ruling out infections).
First-line treatment relies on dapsone, which is usually effective in a few days. The initial daily dose is 100 mg. The dose of dapsone will be adapted to tolerance (hemoglobin, methemolgobin) and efficiency.
Dermatology Nursing. 2008;20(4):274-282. © 2008 Jannetti Publications, Inc.
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