Alternaria Allergy and Asthma in Children

Alternaria alternata is one of the most clinically relevant fungal allergens in pediatric patients with respiratory allergies. Sensitization to this mold has increased in recent decades and is influenced by environmental exposure, geographic location, climate change, and genetic predisposition. In children, Alternaria spp. are strongly associated with the development and worsening of asthma and allergic rhinitis, often contributing to severe and difficult-to-control forms of the disease. The major allergen, Alt a 1, plays a central role in the immunopathogenesis of Alternaria-induced allergies and exhibits molecular features that allow cross-reactivity with other fungal species. Although Alternaria allergy is clinically relevant, its diagnosis remains challenging due to the variability and lack of standardization of fungal extracts. Therefore, it may be necessary to complement traditional diagnostic tools, such as skin prick testing and specific IgE measurement, with component-resolved diagnostics or, in selected cases, nasal provocation tests. Allergen immunotherapy (AIT) has shown promising results in the treatment of Alternaria allergy, particularly with the use of standardized Alt a 1-based extracts or chemically modified allergoids, which offer clinical benefits and immunological modulation. However, AIT is still underused in this context, partly because of the lack of widely available commercial products and long-term efficacy data in the pediatric population. This review provides a comprehensive overview of the current knowledge on the epidemiology, mechanisms, clinical implications, and treatment options related to Alternaria allergy in children, with the aim of supporting early recognition and tailored therapeutic strategies for this important, yet often underestimated, allergen.