Lichenoid Sarcoidosis: A rare form of cutaneous sarcoidosis

Background: Sarcoidosis, also known as Besnier-Boeck-Schaumann disease, is a systemic granulomatous disease of unknown origin that can affect various organs. Cutaneous manifestations are diverse, presenting initially in 80% of cases and being the sole sign of the disease in 25% of patients. Among these manifestations, lichenoid sarcoidosis is a rare form, accounting for only 1 to 2% of cutaneous cases. First described in 1899, it manifests as slightly scaly papules, primarily located on the trunk and face. Although often benign, this form can be associated with ocular and joint complications, especially in children. This article presents a case of lichenoid sarcoidosis in a 44-year-old woman. Methods: we present the case of A 44-year-old woman presented with asymptomatic skin lesions on the trunk and face, evolving over three months. Clinical examination revealed flesh-colored papules grouped on the face, neck, and back. Results: Histological analysis showed non-caseating epithelioid granulomas. Laboratory tests were normal except for elevated ACE levels. Based on clinical and histological findings, a diagnosis of lichenoid sarcoidosis was made, and treatment with hydroxychloroquine and topical corticosteroids was initiated. Discussion: Sarcoidosis is a multisystemic disease of unknown etiology, primarily affecting young adults, with a female predominance. Cutaneous manifestations, present in 20–25% of cases, may be nonspecific (such as erythema nodosum) or specific, featuring non-caseating granulomas. The lichenoid form, first described in 1899, presents as slightly scaly papules, mainly on the trunk and face. Though often benign, it may be associated with ocular and joint complications, particularly in children. In this case, the patient had no pulmonary or ocular involvement, and histological analysis confirmed the characteristics of lichenoid sarcoidosis. The main differential diagnoses include lichen scrofulosorum and other lichenoid dermatoses. Conclusion: This article reports a case of lichenoid sarcoidosis in a woman, illustrating this rare form of cutaneous sarcoidosis, diagnosed based on clinical observation and histopathological analysis.