Increasing Prevalence of Sensitization to Cat/Dog Allergens in the COVID-19 Pandemic

INTRODUCTION

Cat and dog allergens are common indoor triggers for respiratory allergies such as allergic rhinitis and asthma. This study aims to evaluate the prevalence of cat and dog allergies in adults and analyze changes during the COVID-19 pandemic.

METHODS

We retrospectively analyzed the medical records of 8,102 patients who visited an allergy clinic and underwent skin prick testing (SPT) from March 2018 to March 2022: 2 years before and 2 years during the pandemic. Demographic information, clinical attributes, and laboratory results were examined based on patient records.

RESULTS

Of 8,102 SPTs performed, 400 (4.9%) were sensitized to cat allergen and 289 (3.6%) to dog allergen. Allergic rhinitis was the predominant clinical diagnosis in both groups. Of the 400 subjects exposed to cats, 240 (60%) experienced allergic symptoms, while of the 289 subjects exposed to dogs, 65 (22.5%) experienced allergic symptoms during exposure. Within the cat-sensitized group, anaphylaxis was observed in 5 patients (1.3%), while no cases of anaphylaxis were reported in the dog-sensitized group. Compared to the pre-pandemic period, patients presenting during the pandemic had higher rates of cat and dog sensitization (5.7% vs. 4.1%; p < 0.05, 5.2% vs. 1.7%; p < 0.05).

CONCLUSION

During the COVID-19 pandemic, there was an increase in cat and dog allergies among adults. Increased exposure to pet antigens, both directly and indirectly, has resulted in more people becoming sensitized to cats or dogs.

Sensitization to Furry Animals and Clinical Relevance of House Dust Mite-Induced Allergic Rhinitis in Guangzhou, China

INTRODUCTION

The impact of furry animal allergens on house dust mite (HDM)-induced allergic rhinitis (AR) is unclear.

OBJECTIVE

We aimed to investigate the co-sensitization and cross-sensitization of furry animal allergens and assess their clinical relevance with HDM-induced AR.

METHODS

We enrolled 268 patients with HDM-induced AR who were diagnosed with skin prick tests positive for dogs and/or cats. Specific immunoglobulin E (sIgE) for dogs (e1) and cats (e2), their components (Can f 1-5 and Fel d 1-2), and other uncommon furry animal extracts were measured. Symptoms and quality of life were assessed with a visual analog scale (VAS).

RESULTS

The VAS scores for the AR and asthma (AS; n = 166), moderate-to-severe persistent-AR (n = 132), and e1P (positive)-e2P (n = 89) groups were higher than those for single AR (n = 102), other AR classifications, and other AR sensitization profiles, respectively. The IgE positivity rates for components such as Can f 1-3 and Fel d 2 and those for rats, sheep, mice, cows, and horses were highest in e1P-e2P patients. Can f 1-4, Fel d 1, Fel d 2, or the combined allergens were positively correlated with VAS scores. AR combined with AS and sensitization to Can f 4, Fel d 1, or mice were risk factors for HDM-induced AR with VAS scores ≥5.

CONCLUSIONS

Extensive cross-sensitization or co-sensitization was found between Can f 1-3, Fel d 2, or rat, sheep, mouse, cow, and horse extracts. Higher sIgE levels for Can f 1-4 and Fel d 1-2 or a higher number of furry animal allergens lead to more severe symptoms and a reduced quality of life. Combined with AS, sensitization to Can f 4, Fel d 1, or mice were risk factors for moderate-to-severe HDM-induced AR.

Sensitisation to mites and other animal-derived home aeroallergens in children and its concordance as a measure of covariation of sensitisation

BACKGROUND

Sensitisation to home aeroallergens (mites, furry animals and cockroaches) is predominant in patients in our and other areas. Covariation of sensitisation (CS) to these allergens could be due to cross-reactivity or parallel sensitisation.

METHODS

Skin prick tests were performed to common and second-line home aeroallergens, shrimp and tropomyosin in 253 paediatric patients seen in our Unit due to chronic respiratory symptoms. CS among the main allergens was analysed by means of Cohen's kappa coefficient of concordance (κ).

RESULTS

House dust mites (HDM) were the main allergens involved in sensitisation, followed by furry animals, pollens, storage mites (SM), moulds and cockroaches. CS was very good between D. pteronyssinus and D. farinae (κ=0.81), and good between Dermatophagoides and Euroglyphus (κ=0.71), and decreased markedly to poor (κ<0.20) between HDM and SM or cockroaches. CS among SM and cockroaches was moderate to fair (κ=0.21-0.44). CS was good between shrimp and tropomyosin (κ=0.62), but null between shrimp-tropomyosin and HDM (κ=0.01-0.02), and poor to fair between shrimp-tropomyosin and SM or cockroaches (κ=0.06-0.34). CS between cat and dog was moderate (κ=0.50).

CONCLUSIONS

We have shown the usefulness of κ in exploring CS in a population. In our area, with high sensitisation to HDM and other home allergens, CS is limited for most pairs of allergens, pointing to a lower incidence of cross-reactivity than could be expected, especially between HDM and SM or other invertebrates.