Background: Allergy to cow epithelium (ACE) is of great importance in professions whit highly exposed to cattle, such as cattle farmers, veterinarians, being a health problem in this population, because it is their main livelihood. Objective: Characterize the main clinical manifestations and define the sensitization profile of the population allergic to cow epithelium treated in our health area. Methods: Retrospective study including a total of 34 patients with clinical diagnosis of ACE, confirmed by skin tests, IgE levels specific to bovine epithelium and specific allergenic conjunctival provocation test. Age distribution, sex, profession, clinical symptoms, specific IgE levels for other mammalian epithelia, pollens, mites and food. immunoblotting was performed with extracts of cow dander, cow milk, cow saliva, cow urine, and bull urine and 17 sera from patients ACE previously untreated. Results: The mean age of the patients was 38 years, with a slight predominance of males, and with a higher incidence in cattle farmers/ farm workers. Rhinoconjunctivitis occurred in 100% of all cases. 35% of the patients were monosensitized to cow epithelium, the most frequent profile was the association between sensitization to cow epithelium and dust mites and/or pollens (41 %). Sera from most ACE patients show a 20 KDa IgE binding band to cow epithelium, cow saliva, and cow and bull urine, which surely corresponds to the major allergen Bos d2 (bovine lipocalin). 70% of ACE patients also detected an IgE reactive band of approximately 25 KDa in cow and bull urine extracts, Research with protein databases led to the identification of the protein band as a Bos Taurus lipocalin (UniProt Protein ID: A0A3Q1LGU7_BOVIN)
