In patients with vernal keratoconjunctivitis (VKC), allergies are common and household dust, pollen, and animals are among the most prevalent positive allergens, according to research published in Acta Ophthalmologica.
Investigators in Denmark searched publication databases through May 2021 for studies about allergy testing among pediatric patients with VKC. A total of 33 publications were included in this systematic review and meta-analysis.
The study population included 2122 patients with VKC. The studies were conducted in Asia (n=14), Europe (n=14), South America (n=3) and Africa (n=2). Most studies (n=21) evaluated allergens using a skin prick test.
The prevalence of a positive allergy test was 57.7% (95% CI, 52.5%-62.8%; I2, 76%) overall, ranging from 30% to 93%.
Stratified by testing strategy, positive allergy test rates for the skin prick test (n=1173) was 58.2% (95% CI, 51.0%-65.3%; I2, 80%), specific serum immunoglobulin (Ig)E (n=627) was 54.2% (95% CI, 40.7%-67.4%; I2, 89%), total tear IgE (n=222) was 68.7% (95% CI, 51.8%-83.6%; I2, 80%), conjunctival provocation (n=205) was 51.4% (95% CI, 38.0%-64.6%; I2, 65%), and specific tear IgE (n=66) was 58.9% (95% CI, 46.9%-70.5%; I2, 0%).
The most common culprits for causing a positive allergy test were reported as animals, various pollens, house dust mites, foods, and molds.
This analysis may have been limited, as the diagnosis of VKC was unclear in some trials and there was significant heterogeneity observed, likely due to the fact that studies used differing allergy test evaluations and they tested for different allergens.
“57.7% of the patients with VKC are sensitized,” according to the report. “From a clinical point of view, identifying possible clinically relevant allergens provide information that may aid in managing VKC. However, it should be noted that this may only be relevant for a proportion of the patients, and when planning testing and informing patients and parents, it is important to understand that ~40% of the patients do not have any allergies.”
Rasmussen MLR, D’Souza M, Topal DG, et al. Prevalence of allergic sensitization with vernal keratoconjunctivitis: A systematic review with meta-analyses. Acta Ophthalmol. Published online July 18, 2022. doi:10.1111/aos.15212