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Updated: Aug 8, 2026

Basophil Activation Test for Investigation of IgE-Mediated Mechanisms in Drug Hypersensitivity
Published on: September 16, 2011
[A case of drug eruption induced by hydroxyzine pamoate]
Risa Tamagawa1, Norito Katoh, Megumi Nin
1Department of Dermatology, Kyoto Prefectural University of Medicine Graduate School of Medical Science. risat@koto.kpu-m.ac.jp
Abstract:
A 62-year-old woman with rheumatoid arthritis, Basedow's disease and arrhythmia has been treated with antirheumatic, antiarrhythmic drugs and so on. She developed pruritic diffuse erythema with papules on the trunk and extremities 2 days after taking hydroxyzine pamoate for asteatotic eczema. Laboratory data showed increased levels of eosinophils. Histopathological examination revealed a infiltrate of inflammatory cells in the upper dermis. Patch tests with hydroxyzine pamoate and hydroxyzine hydrochloride were positive. From these findings, we diagnosed this case as drug eruption due to hydroxyzine. Her eruption subsided after she discontinued hydroxyzine pamoate and other drugs which were started within 5 days before the onset of the eruption and was treated with systemic steroid, systemic antiallergic drug and topical steroid.
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