Pyoderma Gangrenosum Over Hypertrophic Scar: Report of a Rare Presentation

Pyoderma gangrenosum (PG) is a chronic neutrophilic dermatoses characterised by large ulcer healing with cribriform scar. PG can rarely occur over the healed scar. Its diagnosis depends on clinical morphology and exclusion of other diseases. We report a case of large pyoderma gangrenosum ulcer on a hypertrophic scar since 1 year. Biopsy from ulcer edge was suggestive of PG and hypertrophic scar. The hypertrophic scar had been formed by healing of a large ulcer 2 years back. The ulcer healed to two-third size over next three months with monthly dexamethasone pulse, daily oral steroid and dapsone. This case was unique since the PG ulcer had occurred over a hypertrophic scar. Such a presentation in PG is rare and physicians should be aware of such occurrence of PG.