Alternaria alternata patch tests on a study population of 500 atopic dermatitis patients

Introduction: Literature data on clinical symptoms related to exposure to Alternaria Alternata mostly concern subjects with respiratory atopy, whereas its role in the pathogenesis of atopic dermatitis (AD) has been poorly investigated. The aim of this study was to investigate Alternaria Alternata patch test results and to correlate the results to clinical history and specific IgE.Methods: 500 patients with atopic dermatitis (AD), 222 males and 278 females, underwent patch testing with Alternaria Alternata 2.4% in petrolatum, provided by Lofarma (Milano, Italy). Specific IgE to Alternaria Alternata were detected by prick tests (Stallergenes, France).Results: 38 (7,6%) patients, 13 males and 25 females, proved positive to Alternaria Alternata patch test. Among them, 12 subjects were affected by rhinitis and/or asthma. The most frequently involved skin sites in AD patients sensitised to Alternaria Alternata were the face, the flexural areas of the limbs and the neck. Among patients undergoing skin testing, 64 (12,8%) reacted to Alternaria Alternata prick tests. Discussion: The significance of positive patch test responses to Alternaria Alternata patch tests remains questionable. The possibility that molds may be involved in the development of skin lesions in patch test-positive AD patients, should be checked with specific provocation and elimination procedures, which is particularly difficult, owing to the multifactorial etiology of AD.