Epidemiology of alternaria alternata allergy: a prospective study in 6840 Italian asthmatic children.

BACKGROUND The prevalence of Alternaria Alternata (AA), a mold causing in children severe asthma is scarcely known, also due to the underdiagnosis of AA allergy, frequently due to multiple sensitizations to molds. OBJECTIVE To analyze this issue we prospectively studied all children attending our Division between January 4, 1990 and December 31, 1997. METHODS A total of 6840 children with asthma or allergic rhinitis were evaluated. Diagnosis was established by family and personal history, physical examination, skin prick tests (SPTs) and RAST (Radio Allergo-Sorbent Test) for inhalants including AA. We further evaluated: (1) sensitization only to AA allergens without positivity for additional inhalants; (2) prevalence of AA positivity among children with asthma or allergic rhinitis; (3) concordance between SPTs and RAST for allergy to molds, (4) proportion of children treated with specific immunotherapy (SIT). RESULTS Among the 6840 children 213 were positive to AA (3.3%), only 89/6840 children (1.3%) had AA monosensitization (p = 0.0001), a concordance between SPTs and RAST was present in 21/89 (23.6%) children (p = 0.0009), and only 9 children out of 89 were SIT treated. Concerning the clinical manifestations, 83 had asthma or allergic rhinitis, and 6 had asthma associated with atopic dermatitis. Family history was positive in 82.9% of children. The mean onset of AA sensitivity was at age 4 for males, and at age 5 for females. CONCLUSIONS In childhood, AA allergy is a genetic affection. The SPT concordance with history and clinical examination appears to be operative. Due to life-threatening reactions in children with AA allergy, we suggest that those with suspected inhalant allergy be tested with AA allergens, and treated with SIT if positive.