A suspected adverse drug experience related to a pseudoephedrine-containing product was reported to us and shared some features with the patient described by Cavanah and Ballas [1], who had a pseudoephedrine reaction presenting as the toxic shock syndrome.

A 41-year-old man presented with a history of four episodes of an unusual fixed drug eruption after using a pseudoephedrine-containing product over the preceding 19 years. The first two episodes occurred at 22 years of age when he developed intense pruritus of the fingers approximately 12 hours after the ingestion of pseudoephedrine tablets. This symptom was followed by severe redness, swelling, erythema, heat, and white papules of the fingers, most prominent on the distal phalanges. No concurrent systemic signs or symptoms were noted. The swelling subsided over 7 days and was followed by desquamation of the affected areas ("like a snake shedding its skin") lasting approximately 2 weeks. An identical sequence of events occurred on three subsequent occasions (3, 15, and 19 years later) in association with pseudoephedrine or pseudoephedrine-containing products. In one instance, the exposure consisted of licking the spoon used to administer a cold medicine to one of his children. After these events resolved, the patient noted a transverse groove across each nail plate that started at the matrix and progressed distally with nail growth. The patient denied any active disease, including occurrences of Raynaud phenomenon or symptoms suggesting connective tissue disease.

The reported events are consistent with a fixed drug eruption in that a sharply localized dermatitis occurred at the same site each time the suspect agent was administered. The reason that a drug-induced skin reaction would localize to the distal phalanges is a matter of conjecture. Various medications have been associated with particular lesional distributions [2]. Lesional keratinocytes at the site of fixed drug eruptions may lack the capacity to regulate intercellular adhesion molecule-1 and thereby promote lymphocyte accumulation in those areas. It is possible but unlikely that -agonist effects on peripheral vasculature contributed to this condition because of the dosages used and the known pharmacologic profile of pseudoephedrine.

As in the patient described by Cavanah and Ballas, our patient had desquamation of the hands and multiple positive rechallenges but not systemic signs and symptoms. Fixed drug eruption and pseudoscarlatina with distal desquamation have been reported with pseudoephedrine [3, 4]. Transverse Beau lines can be seen after various illnesses, both systemic and local, including paronychia and periungual dermatitis [5].