Systemic photoallergy to terbinafine

Himly et al. (7) developed a novel in vitro system to detect allergenspecific IgE that revealed an IgE-mediated mechanism in patients with adverse reactions to pyrazolones, mainly cutaneous manifestations with asthma or asthma plus rhinitis. In our patient, the negative responses to skin tests in the presence of naso-ocular symptoms and increase in R = +120 on ARM indicate that a metamizole metabolite may induce the IgE-mediated reaction. This hypothesis fits well with the rapidity of the onset of reaction after metamizole intake (30 min), the absence of asthma (usually present in patients who reacted to blocker of cyclooxygenase-1 agents), and tolerability to aspirin. Asero et al. (8) showed that in patients with urticaria following a single NSAID (other than aspirin), the OCT with aspirin is safe and discriminates between single and multiple reactors according to the tolerance to aspirin or not. Here, because of the negative response to aspirin, it could be argued that not only in cases of urticaria but also in those with respiratory reactions to a single NSAID, the provocation test using aspirin could be used to identify naso-ocular responders to one or multiple NSAIDs. The pyrazolones are drugs that may cause multiform reactions with allergic, nonallergic, or mixed hypersensitivity which warrant further studies.