Can pet keeping be considered the only criterion of exposure to cat/dog allergens in the first year of life?

The Primary Prevention of Atopy: Does Early Exposure to Cats and Dogs Prevent the Development of Allergy and Asthma in Children? A Comprehensive Analysis of the Literature

The current literature shows mixed results relating to the significance of environmental exposure, such as owning a pet, and the development of atopy in children. Our review aimed to collect the most recent evidence on the association between early-life cat and dog ownership and the development of allergy and asthma. A comprehensive literature review was performed using PubMed and Scopus. The search included the main keywords of our PICO: (((early exposure) AND (children) AND (allergy)) OR (asthma)) AND (dog) OR (cat). Randomized controlled trials (RCTs), case-control studies, clinical trials, meta-analyses, and systematic reviews of children within the last five years (2018-2023) were searched and included. During the search process, 52 articles from PubMed and 43 from Scopus were found. A total of 17 articles were deemed to be suitable and included. Fairly consistent results regarding early exposure to pets, in particular dogs, and the prevention of food allergies have been described. Furthermore, there seems to be a protective effect against allergy and asthma in relation to the number of pets owned. The likelihood of a child developing allergy and asthma seems to be influenced by various factors, including the child's genetic background and early exposure to different environmental factors, including allergens that may interact with the gut microbiota and immune system.

Critical aspects in dog allergen immunotherapy (DAI). May Component Resolved Diagnosis (CRD) play a role in predicting the efficacy?

We hypothesize that a pivotal condition determining the efficacy of dog allergen immunotherapy (DAI) might be the mono-sensitization to dog lipocalins (Can f 1-2) in individuals not directly or indirectly exposed to other furry animals. In fact, the concomitant sensitization to lipocalins and/or albumins, especially in those patients directly exposed to furry animals, may potentially stimulate patient's airways by inducing persistent inflammation and, thus, clinical symptoms. In these conditions, it is likely that DAI alone could be inadequate to reduce airway inflammation mediated by inhalation of dog allergens in patients with simultaneous exposure to other furry animals. Can f 5 has been found as exclusive allergen in about one third of dog-sensitized individuals. Considering the presence of different allergenic materials in extract of mammalian origin, it is evident that a standard DAI is not likely to be effective in Can f 5 prevalent or mono-sensitized individuals. Moreover, we would underline the need of collecting detailed information on the possible exposures to furry animals (other than the common pets), an information that usually is neglected in clinical practice. Furthermore, a detailed clinical history exploring the real significance of dog sensitization (mono or poly-sensitization, induction of clinical symptoms after exposure etc.) should be performed before prescribing DAI. In some patients, with potential high susceptibility to animal allergens, the use of CRD is essential to verify the presence of concomitant allergic sensitization to lipocalins and/or albumins belonging to other furry animals. The availability of CRD introduced the possibility of a better targeted prescription of DAI because it might be useful for point out the primary allergens and for the exclusion of cross-reactive ones.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query "are there animals at home?" is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150-20.75%) or indirect contact (103-14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as "exposed to animals" and 510 (70.54%) as "not exposed" according to usual query. Our classification has shown that many "not-exposed" subjects (399-55.19%) were "really exposed". The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Allergic sensitization to common pets (cats/dogs) according to different possible modalities of exposure: an Italian Multicenter Study

Background

The query “are there animals at home?” is usually administered for collecting information on anamnesis. This modality to consider exposure to pet allergens constitutes a potential bias in epidemiological studies and in clinical practice. The aim of our study was to evaluate/quantify different modalities of exposure to cat/dog in inducing allergic sensitization.

Methods

Thirty Italian Allergy units participated in this study. Each centre was required to collect the data of at least 20 consecutive outpatients sensitized to cat/dog allergens. A standardized form reported all demographic data and a particular attention was paid in relieving possible modalities of exposure to cat/dog.

Results

A total 723 patients sensitized to cat/dog were recorded, 359 (49.65%) reported direct pet contact, 213 patients (29.46%) were pet owners, and 146 subjects (20.19%) were exposed to pets in other settings. Other patients were sensitized by previous pet ownership (150–20.75%) or indirect contact (103–14.25%), in 111 subjects (15.35%) any contact was reported.

Conclusions

Only 213 patients (29.46%) would be classified as “exposed to animals” and 510 (70.54%) as “not exposed” according to usual query. Our classification has shown that many “not-exposed” subjects (399–55.19%) were “really exposed”. The magnitude of exposure to pet allergens at home is not related exclusively to pet ownership. These considerations should be taken into account during the planning of epidemiological studies and in clinical practice for the management of pet allergic individuals.

Dog and Cat Allergies and Allergen Avoidance Measures in Korean Adult Pet Owners Who Participated in a Pet Exhibition

Purpose

This study evaluated dog and cat allergies and their association with allergen avoidance measures in Korean adults.

Methods

The study population consisted of 537 adults who currently kept dogs or cats and participated in a pet exhibition in Korea. The subjects were asked to complete questionnaires regarding pet ownership, allergen avoidance, and allergy symptoms, and underwent skin prick tests. They were considered to have a dog or cat allergy if they suffered from one or more of allergy symptoms during contact with their pets.

Results

In total, 103 of 407 dog owners (25.3%) and 45 of 130 cat owners (34.6%) had a dog or cat allergy, respectively. Dog owners kept 1.3±1.5 dogs; this number did not differ according to the presence of dog allergy. Dog owners with a dog allergy had owned their dogs longer than those without (88.0±72.0 vs 67.5±72.7 months, P<0.05). Cat owners kept 2.1±3.6 cats; this number did not differ according to the presence of cat allergy, nor did the duration of cat ownership. Cat owners with a cat allergy had facial contact and slept with their cats less frequently (8.6±11.9 vs 18.3±27.0 times/day, P<0.01; 71.1% vs 81.2%, P<0.05); however, they had their cats shaved and beds cleaned less frequently than those without (1.8±3.3 vs 3.2±4.4 times/year, P<0.05; 1.5±1.5 vs 3.9±6.0 times/month, P<0.01).

Conclusions

Cat owners with a cat allergy tried to minimize contact with their cats, but efforts to avoid indoor cat allergens were lower than those without. In comparison, dog owners with a dog allergy had kept their dogs for longer time than those without; however, current contact with their dogs and allergen avoidance measures did not differ between the 2 groups.