Type I hypersensitivity to nocturnal Lepidoptera in a Costa Rican allergic population

Background: Allergic patients are routinely tested for various allergens including molds, food, pollen, cockroaches and house dust mites; however, there are patients who present allergy symptoms but show negative results in Prick tests with the available allergens. Objectives: To determine the percentage of patients sensitized to the nocturnal Lepidoptera and its role as an important environmental allergen. Material and method: A retrospective analysis was carried out in which we determined the percentage of patients allergic to nocturnal Lepidoptera, house dust mites (Blomia tropicalis, Dermatophagoides pteronyssinus, Dermatophagoides farinae and Tyrophagus putrescentiae) and insects (Periplaneta americana and Musca domestica). Also, we analyzed the demographics and symptoms of the patients. Results: 63% of the patients were allergic to house dust mites, 39% to nocturnal Lepidoptera, 28% to Periplaneta americana and 24% to Musca domestica. Also, 2% of the patients allergic to only one allergen were mono-sensitized to nocturnal Lepidoptera. Conclusions: We strongly recommend that allergists constantly test for nocturnal Lepidoptera, because most of the studied patients had allergy to these insects. Key words: allergy, nocturnal Lepidoptera, moth, Prick test