Vernal keratoconjunctivitis--a rare but serious comorbidity of allergic rhinitis and eustachian tube dysfunction

Allergen Testing: A Review of the Indications, Procedures, and Limitations in Ocular Allergy

Allergen-based diagnostics are essential in the management algorithm of allergic diseases. Unlike systemic allergy, where the indications and interpretation of these diagnostic modalities are well established, their utility in ocular allergy is not well-defined. With the rising prevalence of ocular allergies and the need for personalized treatment strategies, there is a growing demand for precision allergen diagnostics. This review describes the commonly used tests with their indications, procedures, and limitations. A review of the literature was carried out on articles on allergen diagnostics in ocular allergy, and after excluding articles that were not relevant, 82 papers were included in the current review. IgE-mediated pathways contribute significantly to seasonal and perennial ocular allergy and partly to vernal keratoconjunctivitis. Most diagnostic techniques aim to detect IgE sensitization. In vivo tests include skin prick (SPT), intradermal, and patch tests. SPT is considered the gold standard and directly evaluates the presence of allergen-specific IgE in the skin. In vitro tests measure total and specific IgE from either tears or sera. Tear IgE measurement is relatively specific for allergic conjunctivitis and can provide insight into the potential allergens responsible for local sensitization. The conjunctival provocation test can help establish true allergy, especially in patients with polysensitization. This review also provides an overview of evidence in literature segregated based on the test employed. This includes 17 studies on only SPT; 42 studies on IgE measured in serum, tears, or both; and 20 studies which have evaluated both SPT and IgE. The pattern of allergen sensitization can guide recommendations for avoidance measures and immunotherapy. Thus, this could create a corticosteroid-sparing therapy avenue in these patients, reducing disease severity and resulting visual morbidity.

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.

Vernal keratoconjunctivitis: An update

Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are potentially severe and complex disease in its management among the various allergic eye diseases. In this regard, studies clarified the etiopathogenetic mechanisms. The workup should be multidisciplinary. The treatment includes topical and systemic medications with anti-inflammatory and immunosuppressant activity. However, a definition of nationally- and internationally-shared diagnostic protocols would also be needed and validated access to therapeutic options of proven safety and efficacy to avoid the use of galenic preparations, up to now still essential in the management of moderate-severe VKC. Finally, recognizing VKC and AKC, among rare diseases, at a national and international level would be an essential step to allow the management of VKC with adequate timings and settings within the National Health System.

Evaluation of Olfactory Function in Children With Vernal Keratoconjunctivitis

BACKGROUND

Vernal keratoconjunctivitis (VKC) is a chronic, severe allergic disease of the conjunctiva, which mostly affects young males in early to mid-childhood. There is a high incidence of asthma, allergic rhinitis (AR) and eczema among patients with VKC. It is unknown if VKC patients have abnormal olfactory dysfunction, and if so, whether this is related to AR.

OBJECTIVE

Our aim was to evaluate olfactory function in children with VKC, with and without comorbid AR, in comparison to healthy children without VKC.

MATERIALS AND METHODS

Thirty-nine VKC patients and 32 healthy children were included in the study. After eye and ear, nose and throat (ENT) examination, acoustic rhinometry and modified Connecticut Chemosensory Clinical Research Center (CCCRC) tests were performed and the test results were compared between VKC and control groups and between VKC children with or without AR. A p value <0.05 was regarded as statistically significant.

RESULTS

The VKC group included 25 males (64.1%) with a mean age of 11.13 ± 3.22 years, while the control group included 26 males (81.3%) with a mean age of 12.50 ± 2.13 years (p > 0.05 for both age and gender). Fourteen VKC patients (35.9%) had either positive prick test or elevated serum specific IgE levels against house dust mites and pollens. Mean odor thresholds did not differ between the two groups (p = 0.084), while mean odor identification and CCCRC score were statistically significantly lower in VKC group (6.00 ± 1.02 and 6.81 ± 0.75, respectively) compared to control group (7.06 ± 0.77 and 7.5 ± 0.41, respectively) (p < 0.05, both). Thirteen VKC patients had co-associated AR (33.3%). In VKC patients with AR, mean odor threshold and identification scores were even lower (5.31 ± 0.95 and 6.23 ± 0.78, respectively) (p < 0.05, both).

CONCLUSION

Olfactory function was found to be mildly impaired in children with VKC, especially when co-associated with AR. Therefore, loss of smell should be asked as an extraocular symptom.

BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis (Revised Edition 2017; First edition 2007)

This is an updated guideline for the diagnosis and management of allergic and non-allergic rhinitis, first published in 2007. It was produced by the Standards of Care Committee of the British Society of Allergy and Clinical Immunology, using accredited methods. Allergic rhinitis is common and affects 10-15% of children and 26% of adults in the UK, it affects quality of life, school and work attendance, and is a risk factor for development of asthma. Allergic rhinitis is diagnosed by history and examination, supported by specific allergy tests. Topical nasal corticosteroids are the treatment of choice for moderate to severe disease. Combination therapy with intranasal corticosteroid plus intranasal antihistamine is more effective than either alone and provides second line treatment for those with rhinitis poorly controlled on monotherapy. Immunotherapy is highly effective when the specific allergen is the responsible driver for the symptoms. Treatment of rhinitis is associated with benefits for asthma. Non-allergic rhinitis also is a risk factor for the development of asthma and may be eosinophilic and steroid-responsive or neurogenic and non- inflammatory. Non-allergic rhinitis may be a presenting complaint for systemic disorders such as granulomatous or eosinophilic polyangiitis, and sarcoidoisis. Infective rhinitis can be caused by viruses, and less commonly by bacteria, fungi and protozoa.

Vernal-like conjunctivitis in a western lowland gorilla (Gorilla gorilla gorilla)

CASE DESCRIPTION

A 17-year-old female western lowland gorilla presented with bilateral ocular discharge, conjunctivitis, and rhinitis that was investigated and treated over a 34-month period. Clinical findings, diagnostic results, treatment, and follow-up are described.

CLINICAL FINDING

A mild intermittent mucoid ocular discharge was initially noted. 10 months later, conjunctival hyperemia and thickening developed and progressed rapidly to a mass-like lesion covering the right eye. Hematology revealed eosinophilia. Conjunctival cytology revealed eosinophils and neutrophils, and histopathology revealed a chronic proliferative eosinophilic conjunctivitis. 21 months after, the ocular lesions were investigated the gorilla developed masses within both external nares. Histopathology of the nasal lesions revealed chronic-active eosinophilic rhinitis.

TREATMENT AND OUTCOME

Treatment of the gorilla was based on protocols recommended for human patients. Protocols for mild, moderate, and finally severe disease were used, involving topical and oral combinations of treatments. The gorilla eventually responded to systemic immunosuppressant therapy recommended for severe refractory disease.

CLINICAL SIGNIFICANCE

To the authors' knowledge, this is the first reported case of vernal-like conjunctivitis in a western lowland gorilla.