Cat Dander Allergy
The effect of cat removal on allergen content in household-dust samples.
AUTHORS: Wood RA; Chapman MD; Adkinson NF Jr; Eggleston PA
AUTHOR AFFILIATION: Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.
SOURCE: J Allergy Clin Immunol 1989 Apr; 83(4): 730-4
CITATION IDS: PMID: 2708734 UI: 89215042
ABSTRACT:To evaluate the effect of cat removal on cat-allergen content in the home, serial house dust samples were collected from 15 homes during a 9- to 43-week period after cat removal. Samples were obtained with a hand-held vacuum cleaner, and allergen content was quantitated by a radioimmunoassay specific for the major cat allergen, Fel d 1. Baseline Fel d 1 content ranged from 7.8 Food and Drug Administration units per gram of dust to 436.7 U/gm (median 61.2 U/gm), consistent with levels found in homes with a pet cat. Fel d 1 levels declined gradually in most homes, and by 20 to 24 weeks after cat removal, eight of 15 reached levels consistent with levels found in control homes without cats. In two of those homes, allergen levels fell much more rapidly after aggressive environmental control measures were undertaken. In the other seven homes, however, the decline occurred at a much slower rate, with three homes demonstrating persistent elevations in Fel d 1 content for more than 20 or more weeks. These data demonstrate that the task of allergen elimination from an indoor environment is extremely difficult, even when the source of a specific allergen can be identified and removed.
Airborne concentrations and particle size distribution of allergen derived from domestic cats (Felis domesticus). Measurements using cascade impactor, liquid impinger, and a two-site monoclonal antibody assay for Fel d 1.
AUTHORS: Luczynska CM; Li Y; Chapman MD; Platts-Mills TA
AUTHOR AFFILIATION: Department of Medicine, University of Virginia, Charlottesville 22908.
SOURCE: Am Rev Respir Dis 1990 Feb; 141(2): 361-7
CITATION IDS: PMID: 2301854 UI: 90145833
ABSTRACT:The recent development of a sensitive two-site monoclonal antibody immunoassay for the major cat allergen (Fel d 1) has made it possible to make accurate measurements of airborne cat allergen using low volume samplers that do not disturb the room. Houses with cats had from 2 to 20 ng Fel d 1/m3 air compared with less than 0.2 ng/m3 in houses without cats. Using a cascade impactor and a multistage liquid impinger, the particle size distribution of airborne Fel d 1 in nine houses was 75% on particle greater than or equal to 5 microns in diameter and 25% (range, 10 to 62%) on particles less than or equal to 2.5 microns. In a cat vivarium with 12 cats, the air contained 40 ng Fel d 1/m3, but less than 2% was detected on particles less than or equal to 2.5 microns. The air exchange rate in the vivarium (approximately 15 changes/h) appears to be the major difference from domestic houses (less than 0.5 change/h). Repeated studies in one house confirmed a very high proportion (approximately 60%) of Fel d 1 on small particles. During domestic cleaning, the levels of small particle allergen in this house approached those produced by a nebulizer for bronchial provocation, i.e., 40 ng/m3. These results show unequivocally that sufficient airborne Fel d 1 is associated with small particles, which remain airborne for long periods. These findings are strikingly different from previous results obtained with airborne dust mite allergen. The results provide an explanation for the distinctive rapid onset of asthma or rhinitis in patients allergic to cats and a basis for designing a policy to reduce airborne allergen in houses with cats.
Ubiquitous presence of cat allergen in cat-free buildings: probable dispersal from human clothing.
AUTHORS: Enberg RN; Shamie SM; McCullough J; Ownby DR
AUTHOR AFFILIATION: Division of Allergy and Clinical Immunology, Henry Ford Health System, Detroit, Michigan.
SOURCE: Ann Allergy 1993 Jun; 70(6): 471-4
CITATION IDS: PMID: 8507041 UI: 93282617
ABSTRACT:Fel d 1 has been found in almost all houses investigated, including those in which cats have never been present. These observations have not been explained. We measured Fel d 1 in samples of carpet dust from ten newly built model homes, 14 occupied homes, six allergists' offices, five hospital corridors, and three shopping mall stores. We also measured Fel d 1 on T-shirts of persons with and without cats. Measurable amounts of Fel d 1 were found in all the dust samples. Fel d 1 found in older model homes exceeded that found in newer model homes (P<.05). The amounts of Fel d 1 found in allergists' offices, hospital corridors, and retail stores were similar to the amounts found in occupied homes without cats. Fel d 1 was found in all T-shirts sampled and increased with increasing exposure to cats. Our findings confirm and extend previous reports of the ubiquitous presence of cat allergen and are consistent with the hypothesis that Fel d 1 is carried into cat-free buildings on the clothing of people exposed to cats.
TITLE: School as a risk environment for children allergic to cats and
a site for transfer of cat allergen to homes.
AUTHORS: Almqvist C; Larsson PH; Egmar AC; Hedren M; Malmberg P; Wickman M
AUTHOR AFFILIATION: Department of Environmental Health, Karolinska Hospital, Stockholm, Sweden.
SOURCE: J Allergy Clin Immunol 1999 Jun; 103(6): 1012-7.
CITATION IDS: PMID: 10359879 UI: 99289411
ABSTRACT: BACKGROUND: Many children are allergic to furred pets and avoid direct pet contact. The school may be a site of indirect exposure to pet allergens, which may induce or maintain symptoms of allergic diseases.
OBJECTIVE: We sought to investigate airborne levels of cat allergen (Fel d 1) at schools and in homes with or without cats and to study clothes as a route for dissemination of allergens between homes and school.
METHODS: Airborne cat allergen was collected with personal samplers from (1) children attending classes with many (>25%) or few (<10%) cat owners and (2) homes with or without cats. A recently developed amplified ELISA assay, which detects low levels of airborne cat allergen in pet-free environments, was used. Dust samples were collected from clothes and mattresses.
RESULTS: There was a 5-fold difference in the median levels of airborne cat allergen between classes with many and few cat owners (2.94 vs 0.59 ng/m3; P<.001). The median airborne cat allergen concentration in classes with many cat owners was significantly higher than that found in the homes of non-cat owners (P<.001) by lower than that found in homes with cats (P<.001). Allergen levels in non-cat owners' clothes increased after a school day (P<.001). Non-cat owners in classes with many cat owners had higher levels of mattress-bound cat allergen (P=.01).
CONCLUSIONS: The results indicate significant exposure to cat allergen at scool. Allergen is spread through clothing from homes with cats to classrooms. There the allergen is dispersed in air and contaminates the clothes of children without cats. The allergen levels in non-cat owners' homes correlate with exposure to cat allergen at school.