Are cutaneous hypersensitivity tests to inhalant allergens a severity marker for vernal keratoconjunctivitis?

The purpose of this study was to analyze the cutaneous sensitivity to a variety of allergens in patients with vernal keratoconjunctivitis (VKC) and to demonstrate the relation between skin response and clinical aspects of the disease.

Twenty patients with vernal keratoconjunctivitis were randomly chosen from the External Disease and Cornea Sector. They were clinically evaluated, and a score ranging from 0 to 20 was applied based on signs and symptoms on ophthalmic examination. All subjects underwent a skin prick test against standardized allergens, such as house dust mites D. pteronyssinus, D. farinae, and Blomia tropicalis, as well as allergens from cat, dog, fungi and feather.

Seventy-five per cent of patients were positive for at least one of the allergens tested. House dust mites were responsible for the majority of the cases (75%). There was a poor correlation between the clinical score and sensitivity to allergens (r= - 0.119 for fungi; r= - 0.174 for dog; r= - 0.243 for house dust mites; r= - 0.090 for feather). A significant correlation was found only for cat allergen extract (r = - 0.510; p=0.024).

Our study demonstrated poor correlation between cutaneous hypersensitivity tests and clinical findings in patients with vernal keratoconjuntivitis. We concluded that skin response to inhalant allergens is not a useful test to identify clinical severity and chronicity of inflammatory process in this disease.