Toxic bullous dermatoses have frequently engaged the attention of the dermatologist, as is evidenced by the large number of reports of such conditions in medical publications. In reviewing these reports, however, one is struck with the frequent diagnostic difficulties encountered. A bullous eruption produced by a drug, such as an iodide, a bromide, antipyrine or arsenic, is usually identified by a thorough examination of the patient, along with a carefully taken history. Examination of the blood by suitable methods is valuble in cases in which an eruption is suspected of being due to bromide or iodide. Osborne's1 microchemical method of examination of tissues for arsenic might be used in such a condition.
Dermatologists agree that in many cases it is impossible to differentiate between pemphigus and dermatitis herpetiformis and that only the ultimate course can place borderline conditions in the proper classification. Grouven2 expressed the belief that dermatitis