Prevalence of sensitization to animal epithelia allergens in Egyptian patients with respiratory allergy

Abstract

Respiratory allergic disorders can commonly be caused by animals. Animal allergens are mainly derived from mammals, such as cats, dogs, rats, mice, horses, and cows, which secrete or excrete allergens into the environment (Chapman and Wood, 2001). Contact with animals can be for recreational or professional purposes. Cats, dogs, guinea pigs, hamsters, and rabbits are all exceptionally well known pets in industrialized nations, where the rate of pet possession keeps on expanding (Díaz-Perales et al., 2013). Liver, salivary and sweat glands, other body fluids, such as urine, blood and milk are the main sources of animal allergens. The allergens can be effectively dispersed into the surrounding environment as animals shed hair and dander, and secrete and excrete fluids (Zahradnik and Raulf, 2014). Our study was conducted to assess the prevalence of sensitization to animal epithelial allergens by skin prick test (SPT) using standardized allergen extracts and confirmatory specific IgE level (for patients with positive SPT) among Egyptian patients with respiratory allergy (asthma and/or allergic rhinitis). The study included 200 consecutive patients with respiratory allergy including asthma and / or allergic rhinitis recruited from the outpatient clinic of Allergy and Clinical Immunology at Ain Shams university Hospitals. Each patient was subjected to history taking, spirometry, SPT for common environmental aeroallergens and specific IgE for the animal epithelia allergens for patients with positive SPT. Our study showed a female predominance among the respiratory allergy patients with mean age of 35(±11) years. 24.3 % of patients with allergic rhinitis had bronchial asthma and 75.7 % bronchial asthma patients had allergic rhinitis. The greater percentage of bronchial asthma patients had severe persistent asthma (35.5%) while the majority of allergic rhinitis patients had severe persistent rhinitis (62%). Positive was found in 87% of patients. Prevalence of allergy to animal allergens was 44 % and allergy for various other aeroallergens was 56 %. The highest prevalence of sensitization was for cat allergens (30%), followed by horses (28.5%), then dogs (21.5%) then hamsters (13.5%) then rabbit (7.5%) and the lowest prevalence was for guinea pig (1%). The highest sensitivity of specific IgE for animals was 53% for cat specific IgE and 60% for rabbit specific IgE. Our findings suggest that animal allergens are an important contributing factor in respiratory allergy due to their high prevalence among the respiratory allergic patients which was confirmed by SPT and specific IgE. Finally we recommend, larger multi centers case control studies to be carried out in order to determine the prevalence of allergy to animal allergens in respiratory allergic patients including pediatrics, also further studies to determine the role of animal allergens in other types of allergy such as chronic urticaria or atopic dermatitis to be carried out, Further studies should include various allergenic protein components of animal allergens to clarify their role in animal allergy and cross-allergenicity between animal species, It is important to pursue research efforts to understand the role of specific preventive measures in animal handlers for recreational and professional purposes, with preventive prophylaxis programs for such patients for a safer work environment.