The natural history of cutaneous sarcoidosis. Clinical spectrum and histological analysis of 40 cases

BACKGROUND: Cutaneous lesions of sarcoidosis can allow physicians to establish the diagnosis of a systemic disease, but the need of monitoring patients presenting skin limited sarcoidosis in order to detect further extracutaneous involvement has rarely been evaluated. OBJECTIVES: To review clinical and histological features of patients with cutaneous sarcoidosis and the risk of progression to systemic disease. To characterize the phenotype of patients with isolated cutaneous sarcoidosis and to assess the temporal relationship between cutaneous and systemic disease. METHODS: Retrospective review of a series of patients with cutaneous sarcoidosis. Clinical, histopathological, and evolutive features were reviewed. RESULTS: Forty patients were included in the study. Systemic disease was present in 82.5% of patients. Previous or concurrent cutaneous involvement occurred in 81.8% of them. Seven out of 14 patients with cutaneous lesions evolved to a systemic sarcoidosis in a mean time of 6 years, with a range between 4 and 9 years. No clinical or histological differences were found between patients with systemic sarcoidosis and those who showed persistent isolated cutaneous lesions. CONCLUSIONS: Sarcoidosis may be manifested as an isolated cutaneous disorder. No clinical or histopathological features seem to be helpful to discriminate cases of a persistent isolated cutaneous disease from those that will develop systemic involvement. Since the development of systemic involvement in cases of isolated cutaneous sarcoidosis can occur many years afterward, careful monitoring seems advisable, and a long follow-up is recommended.