Serum angiotensin-converting enzyme in sarcoidosis and psoriasis.

Untreated pulmonary sarcoidosis is associated with an increased level of serum angiotensin-converting enzyme (SACE), which is regarded as a valuable method of diagnosing sarcoidosis and measuring the activity of the disease. The level of SACE in cutaneous sarcoidosis or other skin diseases has not been clearly established. We therefore examined SACE in 31 patients with systemic sarcoidosis, including cutaneous manifestations, and 12 patients with isolated cutaneous sarcoidosis. Also, 23 patients with psoriasis were studied. The level of SACE was generally elevated only in patients with untreated systemic sarcoidosis, whereas it was normal in cutaneous sarcoidosis and psoriasis. If the level of SACE is elevated in "isolated" cutaneous sarcoidosis, systemic disease must be strongly suspected.