Skin Reactions to Topical Aminophylline

To the Editor. —Topical aminophylline for reduction of thigh fat was publicized widely after a study in 12 women was presented at the North American Association for the Study of Obesity.1Several products are available over-the-counter, with marketing claims limited to smoother appearing thighs, reportedly to limit controlled testing and scrutiny by the Food and Drug Administration (FDA).2 Since this cream is now widely available to the public, physicians must be aware of possible side effects of topical aminophylline. As early as 1958, localized topical dermatitis was reported in a pharmacist who extemporaneously prepared aminophylline suppositories.3The topical dermatitis is due to a type IV hypersensitivity reaction to the ethylenediamine complexed in the aminophylline molecule.3A more serious dermatologic reaction, exfoliative dermatitis or erythroderma, has also been reported secondary to aminophylline.4The prevalence of ethylenediamine sensitivity in the general population has not been estimated. Ethylenediamine