Factitious panniculitis masquerading as pyoderma gangrenosum

We report a case of factitious panniculitis masquerading as florid pyoderma gangrenosum in a 35-year-old woman. At presentation, she had tender, ecchymotic plaques over the lower trunk and limbs, and several biopsies showed active lobular panniculitis. However, the extensive ulceration that ensued was clinically persuasive for pyoderma gangrenosum. We elected to treat the inflammatory element symptomatically with a range of topical and systemic medications including clobetasol propionate, tacrolimus 0.1% ointment, prednisolone, dapsone, cyclosporin A and mycophenolate mofetil, none of which effected an improvement. The possibility of a factitious aetiology had been suspected from the outset, and when signs of clinical depression emerged, antidepressant therapy was initiated and the ulcers were encased in fibreglass casts. Within a short period, healing commenced and slowly progressed with scar formation. In retrospect, we consider the diagnosis to have been factitious panniculitis on the basis of strong circumstantial evidence and the disparity between the histological and clinical features.