Horse allergens: An underestimated risk for allergic sensitization in an urban atopic population without occupational exposure.

Background: Data on allergic sensitization to horse allergen in modern urban areas are scarce. The aim of this study was to investigate the characteristics of allergic sensitization and the modality of exposure to horse allergens in atopic patients living in an urban area and without occupational exposure to horse and/or horse-derived materials.

Methods: From among 1822 consecutive outpatients, we selected all subjects who had an immediate skin reaction to horse dander.

Sensitization to horse allergens without apparent exposure to horse. Report of two cases.

It has been well established that occupational exposure to horses increases the risk of allergic sensitization to horse hair, on the contrary very few data have been published in individuals without direct contact with horses. We describe two cases of severe respiratory symptoms triggered by a single direct exposure in two patients with only 4-5 previous short contacts with horses during the entire their life, since they live in urban area of Naples. Cutaneous and serological diagnostic tests showed significant sensitization to horse dander other than some common inhalant allergens.

The effect of pet ownership on the risk of allergic sensitisation and bronchial asthma.

An increasing volume of evidence suggests that early contact of children with the allergens of furred pets (especially those produced by cats) may determine a lower risk of developing allergic sensitisation to these materials. A possible explanation of this data is that an early inhalation of high levels of the major cat allergen Fel d 1 induces the production of IgG and IgG4 antibodies with a "protective" effect. Other authors have shown that the prevalence of allergic sensitisation to cats, in adults, is reduced in those patients exposed to the lowest and highest levels of the allergens.