Pyoderma GangrenosumA 5-year-old boy presented with painful skin ulcerations with a red base and purple border. Biopsy samples showed a dense neutrophilic infiltrate; tissue cultures were negative.

Pyoderma gangrenosum is a diagnostic and therapeutic challenge. A misdiagnosis or delayed diagnosis can lead to increased morbidity and death. A fast workup and initiation of treatment is essential. In this review, we present new diagnostic criteria, which can ease the diagnosis, and we summarise the evidence of different treatment modalities. The evidence points towards local immunosuppressive treatment in mild disease, supplemented by systemic glucorticosteroids, ciclosporin or tumour necrosis factor-alpha inhibitors in severe cases. Other biologics are emerging.

SummaryFive patients (four black Nigerian males and one Polynesian) with pyoderma gangrenosum (PG) were seen between May 1974 and March 1984, at the Ahmadu Bello University Teaching Hospital, Kaduna, Nigeria. Their age range was 12–42 years (mean 25.6 years). The female expatriate Polynesian patient had PG localized to the upper back while the other four patients had severe and extensive PG lesions. Local cleansing and dressing of the ulcers combined with appropriate systemic antibiotics produced healing in two of these patients. The empirical addition of dapsone and rifampicin led to complete healing in two others, but only transient remission in one patient who, after 22 years of disease activity, died at home from an aggressive and accelerated form of the disease best described as‘malignant pyoderma’gangrenosum.

This case report describes ulcerative plaques with ill-defined, violaceous, and undermined borders with cribriform scarring.

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that presents with rapidly developing, painful skin ulcers hallmarked by undermined borders and peripheral erythema. Epidemiological studies indicate that the average age of PG onset is in the mid-40s, with an incidence of a few cases per million person-years. PG is often associated with a variety of other immune-mediated diseases, most commonly inflammatory bowel disease and rheumatoid arthritis. The cause of PG is not well understood, but PG is generally considered an autoinflammatory disorder. Studies have focused on the role of T cells, especially at the wound margin; these cells may support the destructive autoinflammatory response by the innate immune system. PG is difficult to diagnose as several differential diagnoses are possible; in addition to clinical examination, laboratory tests of biopsied wound tissue are required for an accurate diagnosis, and new validated diagnostic criteria will facilitate the process. Treatment of PG typically starts with fast-acting immunosuppressive drugs (corticosteroids and/or cyclosporine) to reduce inflammation followed by the addition of more slowly acting immunosuppressive drugs with superior adverse event profiles, including biologics (in particular, anti-tumour necrosis factor (TNF) agents). Appropriate wound care is also essential. Future research should focus on PG-specific outcome measures and PG quality-of-life studies.