Rare scar sarcoidosis: A case report.

A 70-year-old female patient presenting with swelling and subcutaneous nodule formation localized to the knee scars over a two-month period is presently reported. Dermatological examinations found erythematous swelling and small papules on the patient's knee scars, along with subcutaneous nodules beneath and around the scars. Computer tomography of the chest region identified multiple obscure tubercles in the lungs and swollen lymph nodes in the hilum pulmonis and mediastinum. Skin biopsy revealed multiple non-caseating granulomas, which had infiltrated the dermis. The patient was diagnosed with scar sarcoidosis as a result of these observations. The onset of scar sarcoidosis is rare and, therefore, not well understood; however, inflammatory alterations in preexisting scars may be important indicators for disease onset.