INTERSTITIAL GRANULOMATOUS DERMATITIS WITH ARTHRITIS

Background: Interstitial granulomatous dermatitis with arthritis is an uncommon systemic disorder involving the cutaneous and musculoskeleta l systems. The eruption may mimic other dermatoses including granuloma annulare, erythema chronicum migrans, and the inflammatory stage of m orphea. Key histopathologic characteristics, along with clinical corre lation, allow accurate diagnosis. Objective: We describe the clinical, serologic, and histologic features in three patients with interstitia l granulomatous dermatitis with arthritis. Methods: Skin biopsy specim ens were examined and correlated with the clinical and laboratory find ings. Results: Erythematous, annular, indurated plaques on the extremi ties were present in two women. An erythematous, papular eruption on t he head and neck was present in a third patient. All patients had myal gia and migratory polyarthralgias of the extremities along with variou s serologic abnormalities. Histologic examination revealed a dense lym phohistiocytic interstitial infiltrate involving primarily the reticul ar dermis. Foci of necrobiotic collagen were present. Vasculitis was a bsent. Conclusion: Interstitial granulomatous dermatitis with arthriti s is a unique multisystem disease with variable cutaneous expression. Abnormal serologic findings indicate a possible connection to collagen vascular disease.