GRANULOMATOUS HIDRADENITIS SUPPURATIVA AND CUTANEOUS CROHNS-DISEASE

Three patients with concurrent hidradenitis suppurativa and Crohn's di sease are presented. The notable histological feature in each hidraden itis resection was the presence of numerous discrete epithelioid granu lomas in areas of non-inflamed dermis. The purpose of the study was to determine the incidence of epithelioid granulomas in 101 hidradenitis patients and their significance in relation to systemic granulomatous disease. Discrete epithelioid granulomas were identified in 8% of the resections (10 patients). One patient had Crohn's disease and one oth er pulmonary sarcoidosis. Seven patients with granulomatous hidradenit is neither had nor developed any other disease during the 3-year follo w-up period. Clinical review identified a further two patients with Cr ohn's disease but associated with non-granulomatous changes in the ski n resections. Foreign body type granulomas were identified in 25% of t he resections adjacent to ruptured hair follicles, sinus tracts or nea rby degenerate sweat glands. The study shows that, although foreign bo dy type granulomas are a common finding in hidradenitis, the presence of discrete epithelioid granulomas in the dermis away from the site of active inflammation is unusual and should alert the pathologist to th e possibility of systemic granulomatous disease such as Crohn's diseas e or sarcoidosis.