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ALLERGIES ALIVE! |
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CATS |
DOGS |
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Ten per cent of
medical students were found to be allergic to cats in a trial over 10
years 612 medical students who underwent skin prick tests for dog,
cat, timothy grass and birch allergens. Overall allergy to pollen was
reported by 17%, to cats 10%, dogs 5%, to house dust 10%, to molds by
2% and to foods by 15%. Foucard T.
A study by the Red
Cross Blood Transfusion Service in Amsterdam, Netherlands, reports
that in a study of 150,000 subjects on the incidents of cat and dog
allergy an increased relative risk was found from November to January,
perhaps reflecting increased exposure to these pets during the winter.
These data support the hypothesis of a "sensitive" period in
the first months of life during which allergen exposure is more likely
to prime for an allergy later in life. Aalberse RC
Children are more often allergic to cats than to
dogs according to a study of 1238 children in the USA. Children 1 to
17 year old who had respiratory tract allergy were skin prick tested
for cat and dog hair extract. Symptoms after exposure to cats were
significantly more frequent than exposure to dogs. The prevalence of
symptoms and positive skin test reactions to cat allergens increased
with age, significantly more so than the reaction or symptoms after
exposure to dog allergens. The greater frequency of sensitivity to
cats was not caused by exposure to cats in more homes, since dogs
significantly outnumbered cats as the household pet in both atopic and
non-atopic families. However, greater intimacy of exposure to cats
when they were present may have been a factor because cats,
significantly more often than dogs, were inside the house and in the
child's bedroom. Two subgroups were examined to determine whether
those with cat sensitivity who owned cats had more severe symptoms
than those with dog sensitivity who owned dogs. Numbers were small and
differences not statistically significant, but those in the cat
subgroup more frequently had persistent allergic nasal symptoms and
abnormally low spirometric measurements than did those in the dog
subgroup. These findings indicate that children are more often
allergic to cats than to dogs and suggest that the greater frequency
of sensitization to cats may be due to increased intimacy of exposure
to cats. Murray AB.
Cat allergen may exist not only in homes containing
cats but also in homes without cats. A study of house dust was done
from the homes of 106 patients in Baltimore who were attending an
allergy clinic. Animal allergens (cat and dog) were found in 100% of
samples, although there were highly significant differences in antigen
content between homes with and without a particular pet in residence,
many homes without pets contained pet allergens at high
concentrations. Molds were also detected in 100% of homes as well as
house dust mite in 99% of homes. No correlation was demonstrated
between antigen content and symptoms of allergy however.(2)
Cat fleas are considered to be a growing allergy
problem for humans. In one study, out of 70 patients suspected to be
allergic to cats, 46% were found to be allergic to cats and 9% were
found to be allergic to cat fleas, and not cats. This suggests that
some people with suspected cat allergy might be allergic to cat fleas
rather than cats. Rolfsen W et al.
Cat-scratch fever is an infection that usually
results from transmission to humans by the scratch of a cat. Diagnosis
is by evidence of allergy to a certain bacterium (Rothia). It is not
the same as an allergy to cats themselves. Champsuar H.
Passive smoking, amongst other factors,
significantly increases the risk of developing an allergy to cats in
certain types of children according to a study from Paris. de Montis
G.
High-risk children with a high reaction to foods
more often develop inhalant allergy according to a study of 106
children in the Netherlands. Fifty per cent of these children with a
high, and 14% of children with a low anti-food score (IgG1) developed
an allergy to cat dander (IgE). Calkhoven PG et al.
Allergy to cats may exist even in the absence of a
cat in the home. To determine the importance of unnoticed exposure to
cats, a team in Spain studied 20 patients with a history of
respiratory allergy. All the patients had a positive allergy reaction
to cat dander and none of them kept cats as pets. Braso-Aznar JV et
al.
Courtesy of
The Allergy Centre 03 9874 4144
References:
Aalberse RC.
Nieuwenhuys EJ. Hey M. Stapel SO. "Horoscope effect" not
only for seasonal but also for non-seasonal allergens. Clinical &
Experimental Allergy. 22 (11): 1003-6, 1992 Nov.
Braso-Aznar JV,
Pelaez-Hernandez A, Rohchina-Puchades A, Morales-Rubio C, Burches
Baixauli E. Etiologic role of unapparant exposure in cat allergy.
Allergy 50(5):447-50, 1995 May. Denmark
Calkhoven PG,
Aalbers M, Koshte VL, Schilte PP, Yntema JL, Griffioen RW, Van Nierop
JC, Oranje AP, Aalberse RC. Relationship between IgG1 and IgG4
antibodies to foods and the development of IgE antibodies to inhalent
allergens. II. Increased levels of IgG antibodies to foods in children
who subsequently develop IgE antibodies to inhalent allergens.
Clinical & Expermental Allergy. 212(1):99-107, 1991 Jan.
Champsuar H.
Maladie des griffes du chat ou lymphoreticulose benigne d'inoculation.
Une quete continue d'un agent etiologique. Revue de Stomatologie et de
Chirurgie Maxiool-Faciale. 87(1):60-4, 1986. France.
de Montis G.
Constitutional differences in the risk of hypersensitivity to cats in
children. Inegalites constitutionnelles du risque de sensibilisation
au chat chez l'enfant. Annales de Medicine Interne. 142(7):511-4,
1991. France.
Foucard T.
Allergy and allergy-like symptoms in 1,050 medical students. Allergy
46(1):20-6, 1991 Jan. Denmark
Murray AB.
Ferguson AC. Morrison BJ. The frequency and severity of cat allergy
vs. dog allergy in atopic children. Journal of Allergy & Clinical
Immunology. 72 (2): 145-9,1993 Aug.
Rolfsen W,
Schroder H, Tibell C, Tibell M. Detection of specific IgE antibodies
towardss cat flea (Ctenocephalides felis felis) in patients with
suspected cat allergy. Allergy 42(3): 177-81, 1987 Apr.
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Dog allergen
may exist not only in homes containing dogs but also in homes without.
A study of house dust was done from the homes of 106 patients in
Baltimore who were attending an allergy clinic. Animal allergens (cat
and dog) were found in 100% of samples, although there were highly
significant differences in antigen content between homes with and
without a particular pet in residence, many homes without pets
contained pet allergens at high concentrations. Wood RA et al.
Ten per cent of
medical students were found to be allergic to cats in a trial over 10
years 612 medical students who underwent skin prick tests for dog,
cat, timothy grass and birch allergens. Overall allergy to pollen was
reported by 17%, to cats 10%, dogs 5%, to
house dust 10%, to molds by 2% and to foods by 15%. Foucard T.
A study by the Red Cross Blood Transfusion Service
in Amsterdam, Netherlands, reports that in a study of 150,000 subjects
on the incidents of cat and dog allergy an increased relative risk was
found from November to January, perhaps reflecting increased exposure
to these pets during the winter. These data support the hypothesis of
a "sensitive" period in the first months of life during
which allergen exposure is more likely to prime for an allergy later
in life. Aalberse RC et al.
Immunotherapy prevents symptoms of dog allergy after
contact with dogs. Twenty-seven dog-allergic asthmatic children, in
the USA, with no pets in the home were given dog immunotherapy. The
treatment was well-tolerated. No systematic reactions occurred and
local reactions were mild. The results showed a good immunologic
response with a standardized dog dander and hair extract. Valovirta E
et al.
Children are more often allergic to cats than to
dogs according to a study of 1238 children in the USA. Children 1 to
17 year old who had respiratory tract allergy were skin prick tested
for cat and dog hair extract. Symptoms after exposure to cats were
significantly more frequent than exposure to dogs. The prevalence of
symptoms and positive skin test reactions to cat allergens increased
with age, significantly more so than the reaction or symptoms after
exposure to dog allergens. The greater frequency of sensitivity to
cats was not caused by exposure to cats in more homes, since dogs
significantly outnumbered cats as the household pet in both atopic and
non-atopic families. However, greater intimacy of exposure to cats
when they were present may have been a factor because cats,
significantly more often than dogs, were inside the house and in the
child's bedroom. Two subgroups were examined to determine whether
those with cat sensitivity who owned cats had more severe symptoms
than those with dog sensitivity who owned dogs. Numbers were small and
differences not statistically significant, but those in the cat
subgroup more frequently had persistent allergic nasal symptoms and
abnormally low spirometric measurements than did those in the dog
subgroup. These findings indicate that children are more often
allergic to cats than to dogs and suggest that the greater frequency
of sensitization to cats may be due to increased intimacy of exposure
to cats. Murray AB et al.
Courtesy
of The Allergy Centre 03 9874 4144
References:
Aalberse RC.
Nieuwenhuys EJ. Hey M. Stapel SO. "Horoscope effect" not
only for seasonal but also for non-seasonal allergens. Clinical &
Experimental Allergy. 22 (11): 1003-6, 1992 Nov.
Foucard T.
Allergy and allergy-like symptoms in 1,050 medical students. Allergy
46(1):20-6, 1991 Jan. Denmark
Murray AB.
Ferguson AC. Morrison BJ. The frequency and severity of cat allergy
vs. dog allergy in atopic children. Journal of Allergy & Clinical
Immunology. 72 (2): 145-9,1993 Aug.
Valovirta E.
Viander M. Koivikko A. Vanto T. Ingeman L. Immunotherapy in allergy to
dog. Immunologic and clinical findings of double-blind study. Annals
of Allergy. 57 (3): 173-9,1996 Sep.
Wood RA,
Eggleston PA, Lind P, Ingemann L, Schwartz B, Graveson S, Terry D,
Wheeler B, Adkinson NF Jr. Antigenic analysis of household dust
samples. American Review of Respiratory Disease 137(2):358-63, 1988
Feb.
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