Serum allergen specific immunoglobulin E levels in patients with allergic conjunctivitis

Prevalence of allergic sensitization with vernal keratoconjunctivitis: A systematic review with meta-analyses

To determine the prevalence of allergic sensitization in patients with vernal keratoconjunctivitis (VKC) and to provide an overview of published studies on this topic. We systematically searched 11 literature databases on 24 May 2021, for studies with cross-sectional data on the prevalence of positive allergy tests in patients with VKC. Our main outcome of interest was the prevalence of allergic sensitization and the allergens involved. Prevalence meta-analyses were made to provide summary estimates. We identified 33 eligible studies for qualitative review with 2122 patients with VKC. Studies were predominantly based on patients seen in ophthalmology clinics. Overall, studies reported that the most prevalent positive allergen tests were the inhaled allergens house dust mites and pollen. Twenty-nine studies were eligible for the quantitative analysis. Here, we calculated the prevalence of allergen-positive patients to 57.7% (95% confidence interval: 52.5%-62.8%). Subgroup analyses of pooled estimates on sensitization based on specific testing methods found prevalence estimates of 51.4% for conjunctival provocation test, 68.7% for total tear IgE, 58.9% for specific tear IgE, and 58.2% for skin prick test. The prevalence of allergic sensitization in patients with VKC is 57.7%, and mostly towards inhaled allergens. The most frequent positive allergens are house dust mites and pollen. Identifying possible clinically relevant allergens provide information that may aid in managing VKC, such as environmental allergy-avoidance or allergy-specific treatment.

IgE Mediated Wheat Allergy Associated with Resistant and Severe Forms of Allergic Conjunctivitis

Objective:

This study aimed to determine the prevalence and criteria of wheat allergy (WA) among patients with resistant allergic conjunctivitis (AC).

Methods:

A prospective comparative study was conducted on 100 patients with resistant AC. Skin prick-tests (SPTs), total and sIgE against a panel of inhalant and food allergens were performed in all patients’ sera. They were divided into 2 groups according to skin prick test (SPT) and specific IgE (sIgE) level, namely the wheat sensitive group (WSG) and wheat tolerant group (WTG). Total ocular symptom scores (TOSS) and 4-point sign scales were correlated for both groups.

Results:

Ten patients out of 100 with IgE-mediated resistant AC were wheat sensitive, and the other 90 were wheat tolerant patients. WSG included patients of significantly younger age. Positive family history of atopy was proven in 100% of WSG vs. 67% of WTG. A significantly higher frequency of multiorgan allergy was detected in 100% of WSG vs. 20% in WTG (P = 0.0001). Thirty (30%) of WSG had associated allergic rhinitis (AR) and bronchial asthma (BA). Another 30% had an associated AR only, 10% had an associated BA only, and another 20% had an associated skin allergy. TOSS, 4- point sign scale, and total IgE level were significantly higher in WSG.

Conclusion:

This study provides novel evidence that wheat allergy is responsible for some severe forms of AC.

Vernal keratoconjunctivitis in school children in Rwanda and its association with socio-economic status: a population-based survey

Vernal keratoconjunctivitis (VKC) is an allergic eye disease and an important cause of hospital referral among children in Africa and Asia. Hospital-based studies have suggested a role for parasites in its pathogenesis. To determine the prevalence and risk factors for VKC in Central Africa, we conducted a nested population-based case control study in Rwanda, involving randomly selected primary schools from different environments (rural/urban) and climate. A prevalence of VKC of 4.0% (95% confidence interval 3.3-4.7%) was found among 3,041 children studied (participation rate 94.7%). The intestinal parasitic burden was not related to VKC. Besides hot dry climate (odds ratio [OR] = 1.5, P = 0.05) and male gender (OR = 1.7, P = 0.005), multivariate analysis identified higher economic status as a risk for VKC (OR = 1.4, P = 0.005). The effect on VKC of higher economic status appears not to act through differences in parasitic intestinal load.