Background and objective: In areas with a high number of allergens and high allergen concentrations, it is essential to identify the main causes of allergy, especially in pediatric patients. This study was conducted in allergic patients aged 14 or less to identify sensitization profiles during an initial phase, and to then evaluate changes in these profiles after 3 years of follow-up. This article describes the first phase of our investigation.

Methods: A total of 187 patients aged between 2 and 14 years were included by 5 allergy units; all the children had symptoms suggestive of allergic disease (rhinoconjunctivitis and/or asthma). Allergy diagnosis was confirmed by evaluation of clinical history, allergen exposure, and in vivo or in vitro tests. Specific immunoglobulin E (sIgE) to major allergens was tested.

Results: Patients were sensitized to both seasonal (especially grass, olive, cypress and Cynodon dactylon) and perennial allergens (Alternaria alternata) and to panallergens (especially profilin and lipid transfer protein). Almost 60% of the patients included were polysensitized. Sensitization to certain major allergens such as Cup s1, Phl p1, or Sal k1 seems to increase with age. Patients sensitized to profilin had a higher number of sensitizations than non-profilin-sensitized patients. This panallergen is a diagnostic confounding factor.

Conclusions: A high percentage of allergic pediatric patients living in an area with high exposure levels to a large number of allergens are polysensitized and have a high percentage of sensitization to panallergens. The implementation of new diagnostic tools such as component-resolved diagnosis is crucial.

Key words: Allergen exposure. Component resolved diagnosis. Childhood. Allergen sensitization profile.