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- Original article -
The Characteristics of Patients with Atopic Dermatitis Demonstrating a Positive Reaction in a Scratch Test after 48 Hours against House Dust Mite Antigen
Norito Katoh, Shinya Hirano, Mitsuhiro Suehiro, Kouji Masuda and Saburo Kishimoto
Department of Dermatology, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan.
The clinical characteristics of patients in whom an IgE-mediated reaction against house dust mite (HDM) antigens that contribute to the pathogenesis of atopic dermatitis (AD) remain unclear. This study attempted to elucidate the characteristics of patients who exhibit a positive reaction 48 hr or later against HDM in scratch tests. The reactions after epicutaneous application of the allergen to skin with prior scratching were observed for one week in sixteen AD patients showing positive immediate-type hypersensitivity reactions for HDM. Fifty percent of the patients demonstrated positive reactions at 48 hours after epicutaneous application of HDM. Significantly higher values were demonstrated in the group positive for HDM after 48 h in serum total IgE, specific IgE for Der f 1, and lactate dehydrogenase, peripheral eosinophil counts, eruption score, and the area of eruption than in the group negative for HDM after 48 h. Domestic exposure to Der f 1 was also higher in the group positive for HDM after 48 h than in the negative group. These results indicate that the patients in whom the HDM-induced reaction continuing more than 48 h and contributing to their real eczematous eruptions are characterized by considerably increased levels of specific IgE for HDM antigens, high disease activity in AD, and increased exposure to domestic HDM.
Abbreviations: AD: atopic dermatitis, HDM: house dust mite, LC: Langerhans cells, FceRI: high affinity receptor for IgE, DTH: delayed type hypersensitivity reaction
key words: house dust mite; delayed type hypersensitivity reaction; the high affinity receptor for IgE
Received February 10, 2004; Accepted for publication April 12, 2004
Reprint requests to: Norito Katoh, M.D., Ph.D., Department of Dermatology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
J Dermatol 31 (9): 720-726, 2004
Japanese Dermatological Association
http://www.dermatol.or.jp
