To the Editor:— I should like to call attention to an important exception to Dr Ronchese's conclusion (Arch. Dermat. & Syph.46:860 [Dec.] 1942) that "sarcoid and sarcoidosis are attenuated forms of tuberculosis." This statement is reminiscent of the "not even yet dead belief," particularly among specialists in tuberculosis, that erythema nodosum is always, or nearly always, due to tuberculosis. The exception to which I refer is sarcoid (of the skin or of the peripheral nerves) due to leprosy. It is usually referred to by leprologists as "tuberculoid leprosy" or as "the tuberculoid form of neural leprosy," as opposed to nodular, or lepromatous, leprosy. It is characterized by: (1) sarcoid-like cutaneous plaques, which are sometimes annular; (2) anesthesia, always to heat and cold and frequently to light touch as well, either in the lesions or elsewhere; (3) thickening of peripheral nerve trunks (not always present), often in the vicinity