Extraspinal enthesopathy caused by isotretinoin therapy

Objective: To discuss a case of diffuse peripheral enthesopathy in a patien t previously treated with long-term isotretinoin (Accutane) for severe acne . Clinical Features: A 47-year old man with 1 month history of moderate neck and right upper extremity pain, with hypoesthesia of the right second and t hird fingers. Palpable bony prominences around multiple superficial joints were noted on physical examination, raising the initial question of osteoch ondromatosis. Multiple active acne pustules were noted. A limited skeletal survey demonstrated diffuse peripheral enthesophyte formation and hyperosto ses, resembling those of diffuse idiopathic skeletal hyperostosis, but with out accompanying spinal changes. A history of long-term Accutane therapy wa s then elicited. Intervention and Outcome: The enthesopathy was believed to represent an asy mptomatic, longstanding, iatrogenically induced abnormality. No specific th erapy or follow-up was indicated. The patient had discontinued use of Accut ane years ago. Cervical symptoms improved with four sessions of cervical tr action and nonsteroidal anti-inflammatory medications, but upper extremity symptoms were refractory. Conclusion: Accutane-induced enthesopathy should be considered in individua ls with correlating radiologic and clinical features and history of retinoi c acid therapy for acne. This should be a diagnosis by exclusion, after eli minating other potential causes of peripheral enthesopathy, particularly di ffuse idiopathic skeletal hyperostosis, seronegative spondylarthropathy, an d fluorosis.