BackgroundAsthma is the most common chronic disease in children. The aim of this study was to assess the association between asthma severity and skin test reactivity to common inhalant allergens.MethodsWith informed parenteral consent, we included children with asthma, who attended for the first time to Allergy Department and collected data on clinical history, respiratory function and allergic sensitization. Asthma severity was classified using the GINA guide. We integreted the data into regression models to identify allergen sensitization most strongly associated with asthma severity.ResultsWe included 260 children with ages ranging from 3 to 18 years old (mean 11.5 ± 2.85). Male/female ratio: 1.4:1. 72.3% had mild asthma; 23.8% moderate asthma and 3.8% severe asthma. Skin prick testing with aeroallergens was performed. Most of the children were sensitized to at least one aeroallergen (89.6%). Male gender and the number of positive skin tests correlated to asthma severity. Among allergic children 72.1% had more than one allergic disease. Total serum IgE did not correlate with the number of sensitizing aeroallergens, neither with asthma severity. Dust mite was the most frequent sensitization. Cat and molds were associated with a greater risk of having moderate and severe asthma. We found a progressive sensitization with age.ConclusionsSensitization to some perennial indoor allergens, particularly cat and molds, were strongly associated with asthma severity.