ADVERSE REACTION TO PSEUDOEPHEDRINE

A patient developed a scarlatina-like rash on two separate occasions a fter receiving a dose of pseudoephedrine. Patch tests with this substa nce and other structurally related substances (i.e., ephedrine, phenyl ephrine, and epinephrine) were negative. The oral test with pseudoephe drine provoked a new episode. It is difficult to clarify the exact mec hanism of the described reaction; the nature of this eruption probably resembles many other drug-induced adverse reactions in which there is no certainty if mechanisms of type I or III are involved.