Allergic Reaction to Dinitrophenol

Dinitrophenol has been introduced recently as a therapeutic agent in obesity, 1 its effectiveness arising by virtue of its ability, in small doses, to increase the basal metabolic rate. It is claimed that use of the drug is not accompanied by the unpleasant and dangerous side actions inherent in the use of thyroid gland extract; but its proponents state 1b that: The most important side action encountered was a skin rash, observed in eight patients, or 7 per cent of the entire series. This was manifested, usually after a one day prodrome of mild itching, by a maculopapular or urticarial type of rash. The itching was rather intense, and with the urticaria there was considerable swelling. If the drug was withdrawn, the reaction subsided in from two to five days.... In three of the patients, dinitrophenol treatment was successfully resumed after the skin reaction subsided, without recurrence. This type of