Alternaria Sensitization and Allergy in Children and Adolescents: A Retrospective Diagnostic Study

Alternaria alternata (AA) grows on decaying material. Spores occur on hot and dry days in the summer and can trigger asthma and allergic rhinitis. Skin prick test (SPT-AA) and Alternaria alternata-specific IgE (AA-IgE) are used for diagnostic purposes, but their predictive value is unclear.

A retrospective analysis of electronic medical records to 2011-2021 was performed on symptoms, SPT-AA, AA-IgE, lung function, asthma therapy and bronchial provocation using Alternaria alternata extract (BP-AA).

149 children and adolescents (5-18 years) with Alternaria allergy were investigated. Between June and September, 86 Alternaria-sensitized patients had asthmatic symptoms and 113 had nasal symptoms (often outdoors or with mold exposure). SPT-AA and AA-IgE levels did not differ between the symptomatic and asymptomatic patients (SPT-AA, p= 0.23). A weak correlation was observed between the diagnostic tests in 49 patients with bronchial and/or nasal symptoms (r= 0.36, p= 0.01). Nineteen patients received provocation, 16 showed an early asthmatic response and 14 a late asthmatic response. Patients with BP-AA had a medium SPT-AA ≥7 mm or AA-IgE ≥16.8 kU/L. Both tests significantly correlate with PD20-AA (r= -0,49, p< 0.01 and r= 0.26, p< 0.01, respectively).

The Diagnosis of Alternaria allergy is still a challenge. The weak to moderate correlation between SPT-AA and AA-IgE seems to be allergen-specific. Typical medical history is a key diagnostic criterion. Allergy profiles and climate may play a role in the manifestation of symptoms. BP-AA help to establish threshold values for SPT-AA and AA-IgE. In unclear cases, nasal or bronchial provocation should be performed before immunotherapy.