Abstract / Summary
ABSTRACT Background Subcorneal pustular dermatosis (SPD), or Sneddon–Wilkinson disease, is a rare, relapsing pustular skin condition of unknown cause, characterised by subcorneal pustules. Objectives To summarise the demographic, clinical, histopathological, management and disease course of SPD. Methods A systematic review was conducted following PRISMA guidelines including all peer‐reviewed, English‐language studies reporting one or more SPD cases. Results A total of 169 studies (17 case series, 152 case reports) and 205 patients were identified. The median age at diagnosis was 50 years, with a female‐to‐male ratio of 1.77:1. Over two‐thirds of patients had no comorbidities. Monoclonal gammopathy of unknown significance (MGUS) was the most common comorbidity (9.8%), followed by connective tissue disease (7.3%). Clinical pustules were observed in 92.3% of patients, most commonly affecting the trunk (75.1%), limbs (62%), axilla (44.4%) and groin (36.1%). Pruritus was the most common symptom (44.9%), with pain, burning, or irritation occurring in 16.3%. The median time to diagnosis in cases presenting with rash only was 3 years. A precipitant was identified in 22.9% of cases, including infections, flare of underlying condition, or medications such as calcium channel blockers, TNF‐α inhibitors, and antibiotics. In patients who had histopathological findings reported, subcorneal pustules and perivascular infiltrate most common. Dapsone was the most frequently used treatment (133/189, 70.4%), achieving complete response in 33.8%. Topical and systemic corticosteroids achieved complete responses in 22.5% and 29.6%, respectively. Biologics, mostly TNF‐α inhibitors, were used in 11.6%, with complete and partial responses in 63.6% and 27.3%. Limitations The review's findings are limited by a limited sample size of heterogeneous, observational data, which can be prone to publication bias, so conclusions on SPD's clinical features and treatment efficacy should be interpreted cautiously pending larger, controlled studies. Conclusions SPD remains a diagnostic and therapeutic challenge, with frequent delays and limited effectiveness of current treatments. These findings underscore the urgent need for prospective studies and targeted therapies to improve outcomes in this rare dermatosis. Systematic Review Registration PROSPERO CRD42022344461.