This interesting case of pulmonary sarcoidosis and Mycobacterium ulcerans ulcers raises many issues: 1. Our paucity of knowledge of deficient immune status in individuals; the multifarious presentation as recognisable ill health, its early detection, treatment and its prevention. In this present case the management of the immune status of the patient has not yet been fully addressed. The relationship between his pulmonary sarcoidosis as being an 'immune' response to the Mycobacterium ulcerans remains speculative; for example, did this patient have the Mycobacterium infection before he was diagnosed as having sarcoidosis? There is no evidence of this. With the history of repeated cellulitis associated with his business trips to Asia and the Middle East, the likelihood seems speculative--as would infection with Mycobacterium ulcerans contracted from swimming in pools and rivers. 2. As sarcoidosis is thought to have an association with Mycobacterium tuberculosis it is tempting to suggest that as, in this case, the Mycobacterium ulcerans is the caus-ative agent for his sarcoidosis. Additionally, should we be looking for sarcoidosis in every other case of Mycobacterium ulcerans infection? Other cases of Mycobacterium ulcerans could be assessed. 3. It is suggested that corticosteroids do pave the way for opportunistic infection as in this case. How often does this occur in 'usual practice' where patients are exposed to corticosteroids? Further comments are invited. 4. The question of sterility techniques in the home (daily dressings), the surgery, and at work as a food handler, is noted as a matter of concern. 5. The implications of the problem having any work-related association is also noted in passing.