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Furry animals allergy
(Dogs & Cats)
Lalita Tearprasert; M.D.
Scope
Introduction
Prevalence
Cats & Dogs allergens
Clinical effects of allergen exposure
Diagnosis
Environment control
Most persons in Western societies spend more than 90%
of their lives in indoor environments, it is not surprising that
ind...
Prevalence
Rönmark et al. J Allergy Clin Immunol. 2009 August ; 124(2): 357–6415.
‣ Germany, Data were collected from 2003 to 2006
‣ 17,641 children and adolescents
Schmitz et al. Int Arch Allergy Immunol...
Gent et al. Environ Res. Author manuscript; available in PMC 2013 October 01.
Pumhirun et al. Asian Pasific Journal Of Allergy And Immunology (1997) 15: 183-185.
100 cases
female: 59, male: 41
aged be...
Paskorn et al. Asian Pasific Journal Of Allergy And Immunology (2009) 22: 91-95.
THAILAND3-15 years
Bunnag et al. Asian Pasific Journal Of Allergy And Immunology (2009) 27: 79-86.
Percentage of positive skin prick test
- h...
Cat & Dog allergens
Taxonomy
Cat & Dog allergen : Small particles 2-15 micron
( Mites 10-40 micron, Cockroachs > 10 micron )
The primary source of cat ...
Middleton's 8th edition
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
Can be inh...
Middleton's 8th edition
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
Airborne a...
Middleton's 8th edition
The particles of dander carrying cat allergens appear to be “sticky” ,
which means that they are c...
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
http://www.asthmacenter.com/index.php/news/details/pet_allergy/
Environmental assessment and exposure control 2012 : a pra...
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
Major allergens
Middleton's 8th edition
Lipocalins
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
More than 50% of the
furry animal allergens
Small, secreted proteins
A group of proteins involved as ligand transport proteins with
enzymatic activity, participating ...
Cat lipocalin
1.) Fel d 4
2.) Fel d 7
Dog lipocalin
1.) Can f 1
2.) Can f 2
3.) Can f 4
4.) Can f 6
Lipid-binding activity...
Albumins
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
Minor allergens
Fel d2 : Pork-cat syndrome
(associated with allergic symptoms on
eating pork but might not be an
inhalant ...
Cats allergens
Middleton's 8th edition.
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
The major cat allergen is...
Fel d 1 (Secretoglobin)
Major cat allergen : up to 95% of all patients with cat allergy react to Fel d 1
Size 14 kDa
Appea...
No important cross-reactivities with other mammalian
Spread to the environment through airborne dander
The biological role...
Fel d 2 (Albumin)
Middleton's 8th edition
Environmental assessment and exposure control 2012 : a practice parameter—furry ...
PORK- CAT SYNDROME
Primary sensitization is related to environmental exposure to cat albumin
Cross-reactivity between cat ...
Occur within 30–45 min and can occur as rapidly as oral itching during the
meal
Onset of a “new” food allergy in an older ...
Fel d 4 (Lipocalin)
Found primarily in cat saliva
It is an important cause of allergic sensitization in part because of
ex...
Fel d 5 (Cat IgA)
Major IgE binding epitope on cat IgA is "Alpha-gal"
which is associated with delayed anaphylaxis to red ...
Saleh et al. Clinical and Molecular Allergy 2012, 10:5.
Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ;...
Middleton's 8th edition
Saleh et al. Clinical and Molecular Allergy 2012, 10:5.
Commins and Platts-Mills. Curr Allergy Ast...
Saleh et al. Clinical and Molecular Allergy 2012, 10:5.
Loan Star Tick (USA)
- most in Southern
Amblyomma americanum
European Castor bean Tick (Europe)
Paralysis Tick (Australia)
Ixodes holocyclus
Saleh et al. Clinical and Molecular Allerg...
Cause
Alpha-gal is not naturally present in humans, but is all other mammals
Primary exposure causing sensitization to alp...
Diagnosis : A detailed history can help in achieving diagnosis
- type of ingested foods
- time to onset of symptoms
- the ...
Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
IgE responses to different cat components can be induced through
...
Dogs allergens
Middleton's 8th edition
Environmental assessment and exposure control 2012 : a practice parameter—furry ani...
Can f 1 (Lipocalin)
Major dog allergen
Size 23-25 kDa
Secreted from canine Von Ebner's glands
Found in dog hair, dander, a...
288 healthy dogs
Levels of Can f 1 on fur vary between
breeds, gender, hormonal status,
hair length, and according to the
...
Breeds (Labrador retriever), sex and seborrhea seem to influence
the levels of Can f 1 on fur
Ramadour et al. Allergy 2005...
Can f 2 (Lipocalin)
Found in dander and saliva
IgE cross-reactivity was demonstrated between Can f 2 and
the cat allergen ...
Can f 3 (Albumin)
Albumin seems to be a common cross-sensitizing allergenic
component
Obviously found in all dogs >> makes...
Can f 5 (Kallikrein)
Similar to prostatic kallikrein
Found in up to 70% of patients with dog allergy
No patterns of cross-...
Sensitization (Development of allergen specific IgE) in
susceptible individuals
If the exposure persists, often leading to...
Threshold level for allergen exposure
Cats Dogs
Sensitization level
(mcg/g.)
1 2
Theshold level
(mcg/g.)
8
(Fel d 1)
10
(C...
Early exposure
Good or bad ??
For many years, it was assumed that living in a house with a cat
increased the risk of allergy
In 1999, Hesselmar et al. r...
Chen et al. J Allergy Clin Immunol 2007;119:1148-55.
Chen et al. J Allergy Clin Immunol 2007;119:1148-55.
Higher cat allergen exposures from both parent and children mattresse...
Chen et al. J Allergy Clin Immunol 2007;119:1148-55.
Age and parental history of allergy were significant risk factors for...
Pets and Asthma. PLoS One. 2012;7(8):e43214.
Finland
All children aged 1–4 yr (N = 4779)
Born between 2001 and 2005
Cross-sectional questionnaire data on pet exposure ...
Independently of allergic family history,
the incidence of a positive test for
either dog or cat allergens was higher
and ...
1.) Although exposure to elevated cat allergen Fel d 1
concentrations before 3 months of age may reduce the
likelihood of ...
Hypoallergenic pets
In 2004, Allerca Lifestyle Pets, a company based out of San Diego,
California, began to market “hypoal...
“ There was no evidence for differential shedding of allergen
by dogs grouped as hypoallergenic ”
Nicholas E. et al. Am J ...
Because 1 or more cat/ dog allergens are present
in all cats/ dogs, patients should not be advised that
it is safe to obta...
Diagnosis
History of pet exposure
Skin prick test / Specific IgE
Challenge/ provocation test
Environmental assessment and ...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
Dog epithelium
1:20 (W/V)
Cat hair...
Wood et al. J Allergy Clin Immunol 1999;103:773-9.
Wood et al. J Allergy Clin Immunol 1999;103:773-9.
Wood et al. J Allergy Clin Immunol 1999;103:773-9.
Wood et al. J Allergy Clin Immunol 1999;103:773-9.
This study clearly supports the value of SPTs and RASTs
in the diagnosis of cat allergy. Although not perfect,
a positive ...
Environment control
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
1.) Avoidance/ Removing pets from ...
By the 20 th week after cat removal,
levels 8/15 homes were within or
very close to the upper
95% confidence limit of the
...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
2.) Reduce exposure to allergens
T...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
2.1) Removing reservoirs
Carpeting...
Mattress encasings
- Some woven microfiber bed encasings, generally those with a mean
pore size of 6 micron or less, block...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
2.2) Removing allergens from pets
...
Suggested that cats should be bathed in tap water or pet shampoo
for at least 3 minutes to solubilize Fel d 1
Avner et at....
Immersion of cats in water for 3 minutes produced a highly significant
reduction in airborne allergen 3 hours later, but t...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
HEPA air cleaners run continuously...
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
2.5) Chemical treatments
Chemical ...
Sufficient control of exposure to cat allergens to improve
health requires a combination of measures, such as removing
res...
SHARMA et al. Pediatr Clin N Am 54 (2007) 103–120.
Middleton's 8th edition
Environmental assessment and exposure control 2012 : a practice parameter—furry animals
Cat hair e...
Immunotherapy
Exposure to both dog and cat allergen has been shown to be ubiquitous
and can occur even without an animal in the home, ma...
The first randomized double-blind placebo-controlled trial using SCIT
for cat-induced asthma was reported in 1984.
- recei...
Lilja et al. J Allergy Clin Immunol 1989;83 :37-44.
Alvarez-Cuesta et al. J Allergy Clin Immunol 1994;93:556-66.
" Standardized cat extract IT "
Allergen immunotherapy 2011 : a practice parameter third update
SCIT has shown real benefit in cat-allergic patients with
allergic asthma and allergic rhinoconjunctivitis. The data
for d...
Thank you
Furry animals allergy (Dogs and Cats)
Furry animals allergy (Dogs and Cats)
Furry animals allergy (Dogs and Cats)
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Furry animals allergy (Dogs and Cats)

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Furry animals allergy (Dogs and Cats)

Presented by Lalita tearprasert, MD.

December18, 2015

Published in: Health & Medicine
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Furry animals allergy (Dogs and Cats)

  1. 1. Furry animals allergy (Dogs & Cats) Lalita Tearprasert; M.D.
  2. 2. Scope Introduction Prevalence Cats & Dogs allergens Clinical effects of allergen exposure Diagnosis Environment control
  3. 3. Most persons in Western societies spend more than 90% of their lives in indoor environments, it is not surprising that indoor allergens play an important role in allergic sensitization and symptoms American Pet Products Manufacturers Association survey from 2010 - 93.6 million cat owners in the United States - 77.5 million dog owners in the United States Indoor exposures are of great importance in relation to asthma Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Salo et al. J Allergy Clin Immunol 2008;121:678-84. Environmental assessment and exposure control 2012 : a practice parameter—furry animals Introduction
  4. 4. Prevalence
  5. 5. Rönmark et al. J Allergy Clin Immunol. 2009 August ; 124(2): 357–6415.
  6. 6. ‣ Germany, Data were collected from 2003 to 2006 ‣ 17,641 children and adolescents Schmitz et al. Int Arch Allergy Immunol 2013;162:263–270.
  7. 7. Gent et al. Environ Res. Author manuscript; available in PMC 2013 October 01.
  8. 8. Pumhirun et al. Asian Pasific Journal Of Allergy And Immunology (1997) 15: 183-185. 100 cases female: 59, male: 41 aged between 10-59 years, mean age 27.9 years who were diagnosed with AR by history and clinical presentation underwent a prick skin test with 30 aeroallergens THAILAND
  9. 9. Paskorn et al. Asian Pasific Journal Of Allergy And Immunology (2009) 22: 91-95. THAILAND3-15 years
  10. 10. Bunnag et al. Asian Pasific Journal Of Allergy And Immunology (2009) 27: 79-86. Percentage of positive skin prick test - house-dust mite 64.7% - house dust 64% - Bermuda grass 52.3% - cockroach 49.8% - para grass 49.4% - sedge 45.9% - careless weed 45.4% - dog 44.2% - cat 39.3% - Cladosporium 38% Common causative allergens in AR between 2002 and 2004 at ENT Allergy Clinic at Siriraj Hospital : 736 patients THAILAND
  11. 11. Cat & Dog allergens
  12. 12. Taxonomy
  13. 13. Cat & Dog allergen : Small particles 2-15 micron ( Mites 10-40 micron, Cockroachs > 10 micron ) The primary source of cat and dog allergens is dander coming off the skin Airborne : becomes airborne with minimal disturbance, remains airborne for a long time (many hours) Approximately 60% of airborne Fel d 1 settles out within 2 days of disturbance, leaving smaller particles that can remain airborne for up to 14 days or longer Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Erwin EA. et al. Immunol Allergy Clin N Am. 2003; 23:469-81. Environmental assessment and exposure control 2012 : a practice parameter—furry animals The effects of cats/ dogs in the home
  14. 14. Middleton's 8th edition Environmental assessment and exposure control 2012 : a practice parameter—furry animals Can be inhaled into the smaller airways more easily than larger particles, such as mite feces or pollen grains The presence of a cat can increase airborne Fel d 1 within 30 minutes Factors that lead to increase cat allergen concentrations (Fel d1) in house 1.) Increasing numbers of cats in the home 2.) Low ventilation rate 3.) Presence of upholstered furnishings 4.) Carpeting (Other characteristics of cats, such as length of cat hair, cat sex, reproductive status, and time spent indoors, were not associated with levels of Fel d 1)
  15. 15. Middleton's 8th edition Environmental assessment and exposure control 2012 : a practice parameter—furry animals Airborne allergen was being carried on smaller particles (less than 5 µm in diameter) 1.) Small particles fall slowly and can be kept airborne by any movement in the house 2.) Increased ventilation helps to remove small particles from a house 3.) Air filtration with a room air cleaner may be a useful method of reducing exposure to allergen on small particles Airborne allergen Remains airborne (higher total quantity inhaled) : Cat, Dog, Rodent Transiently airborne : Mite, Cockroach
  16. 16. Middleton's 8th edition The particles of dander carrying cat allergens appear to be “sticky” , which means that they are consistently carried on clothing from houses with an animal to other buildings Possible to measure cat allergen airborne in many homes without a cat Sensitization to cats can occur without direct exposure to the animals 75% of the children who are allergic to cats have never lived in a house with a cat Passive transfer of allergens
  17. 17. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
  18. 18. http://www.asthmacenter.com/index.php/news/details/pet_allergy/ Environmental assessment and exposure control 2012 : a practice parameter—furry animals Carpets (Rugs) : Major reservoirs
  19. 19. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Major allergens
  20. 20. Middleton's 8th edition
  21. 21. Lipocalins Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. More than 50% of the furry animal allergens
  22. 22. Small, secreted proteins A group of proteins involved as ligand transport proteins with enzymatic activity, participating in cell homeostasis Found in dander, saliva, and urine; sticky particles Share sequence identities of only 20% to 30% Some lipocalins display much higher sequence identities (about 60%) and cross-react : Can f 6, Equ c 1, and Fel d 4 Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. W. Smith et al. Clin Exp Allergy 2004; 34:1732–1738.
  23. 23. Cat lipocalin 1.) Fel d 4 2.) Fel d 7 Dog lipocalin 1.) Can f 1 2.) Can f 2 3.) Can f 4 4.) Can f 6 Lipid-binding activity of the lipocalins may be a factor that promotes the induction of allergic responses (Th2) W. Smith et al. Clin Exp Allergy 2004; 34:1732–1738.
  24. 24. Albumins Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
  25. 25. Minor allergens Fel d2 : Pork-cat syndrome (associated with allergic symptoms on eating pork but might not be an inhalant allergen) Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Cat lipocalin 1.) Fel d 2 Dog lipocalin 1.) Can f 3
  26. 26. Cats allergens Middleton's 8th edition. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. The major cat allergen is Fel d 1 Purification of Fel d 1 by Ohman et al. in 1974 More than 90% of all people who have respiratory tract symptoms (Asthma, Rhinitis) related to cat exposure have IgE antibodies specific for Fel d 1
  27. 27. Fel d 1 (Secretoglobin) Major cat allergen : up to 95% of all patients with cat allergy react to Fel d 1 Size 14 kDa Appears to be a unique marker for the presence of cats All natural breeds of cat produce Fel d 1 Males producing a larger amount than females Primarily produced in sebaceous, anal, and salivary glands Mainly present in the epidermis and fur (root > tip) The highest concentrations being found on hair from the neck Middleton's 8th edition. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  28. 28. No important cross-reactivities with other mammalian Spread to the environment through airborne dander The biological role of secretoglobin is unknown Allergenicity of inhaled Fel d 1 can be increased by its binding to the mannose receptor on dendritic cells, thereby initiating the process of internalization and the production of Fel d 1–specific IgE and IgG1 Middleton's 8th edition. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  29. 29. Fel d 2 (Albumin) Middleton's 8th edition Environmental assessment and exposure control 2012 : a practice parameter—furry animals All cats have this allergen Size : relatively large (62-kD) protein Target of IgE antibodies in approximately 10% of cat-allergic subjects Cross-reacts immunologically with several different mammalian albumins, including those of dog, pork, and beef >> Pork-cat syndrome
  30. 30. PORK- CAT SYNDROME Primary sensitization is related to environmental exposure to cat albumin Cross-reactivity between cat and pork albumin Can affect children and adults. Majority being adults or teens Presenting with food-related or idiopathic urticarial or anaphylactic symptoms : Allergic reactions to pork Both pork–cat and alpha-gal food allergies are IgE-mediated, and can show similar responses with certain skin tests and immunoassays Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77.
  31. 31. Occur within 30–45 min and can occur as rapidly as oral itching during the meal Onset of a “new” food allergy in an older child or adult may merit consideration of pork–cat syndrome as a diagnosis, especially if a history of tick bites is absent Most of these patients report reactions to pork 10% to 20%, report reactions to beef No cases with reactions to cow's milk have been reported Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77.
  32. 32. Fel d 4 (Lipocalin) Found primarily in cat saliva It is an important cause of allergic sensitization in part because of extensive allergen cross-reactivity with horse (Equ c 1), mouse (MUP1), rat (Rat n 1), and dog (Can f 2, Can f 6) Cross-reactivity of Fel d 4 with dog allergen suggests a role in cosensitization between cat- and dog-allergic patients Highly homologous to the major horse allergen Equ c 1 Middleton's 8th edition W. Smith et al. Clin Exp Allergy 2004; 34:1732–1738. Environmental assessment and exposure control 2012 : a practice parameter—furry animals Fel d 4 >> Can f 2, Can f 6, Equ c 1
  33. 33. Fel d 5 (Cat IgA) Major IgE binding epitope on cat IgA is "Alpha-gal" which is associated with delayed anaphylaxis to red meat IgE to alpha-gal is not associated with rhinitis or asthma Main source of cat IgA is saliva Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  34. 34. Saleh et al. Clinical and Molecular Allergy 2012, 10:5. Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77. Alpha-gal is an oligosaccharide : galactose-alpha-1,3-galactose - IgE antibodies will bind to any proteins that carry this oligosaccharide - found in mammalian cells of non-primates - present in beef, pork, lamb and cat dander - absent in chicken and fish Symptoms : 2 distinct forms of anaphylaxis 1.) Immediate onset anaphylaxis during first exposure to IV cetuximab 2.) Delayed onset anaphylaxis 3–6 h after ingestion of mammalian food products (e.g., beef and pork) >> Red meat syndrome ALPHA-GAL ALLERGY
  35. 35. Middleton's 8th edition Saleh et al. Clinical and Molecular Allergy 2012, 10:5. Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77. Delayed anaphylaxis to red meat 3-6 hr. after ingestion - identified IgE antibodies to the oligosaccharide galactose-α-1,3-galactose (“alpha-gal”) Majority of children with this syndrome present with urticaria rather than acute episodes of delayed anaphylaxis First report that tick bites could give rise to allergic reactions to meat was made by Dr. Sheryl Nunen to the Sydney Allergy Society in 2006 >> published in 2009 >> In 2012 confirmed in Australia and Europe (other tick species) RED MEAT SYNDROME
  36. 36. Saleh et al. Clinical and Molecular Allergy 2012, 10:5. Loan Star Tick (USA) - most in Southern Amblyomma americanum
  37. 37. European Castor bean Tick (Europe) Paralysis Tick (Australia) Ixodes holocyclus Saleh et al. Clinical and Molecular Allergy 2012, 10:5.
  38. 38. Cause Alpha-gal is not naturally present in humans, but is all other mammals Primary exposure causing sensitization to alpha-gal is from tick bites (Tick feed on another mammal, alpha-gal will remain in its alimentary tract) Tick bite will inject the alpha-gal into host Saleh et al. Clinical and Molecular Allergy 2012, 10:5. Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77. Release IgE antibodies to foreign carbohydrate
  39. 39. Diagnosis : A detailed history can help in achieving diagnosis - type of ingested foods - time to onset of symptoms - the geographic area of residence as well as history of tick bites Saleh et al. Clinical and Molecular Allergy 2012, 10:5. Commins and Platts-Mills. Curr Allergy Asthma Rep. 2013 February ; 13(1): 72–77. Investigations - sIgE to pork, beef, cat albumin, alpha-gal
  40. 40. Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. IgE responses to different cat components can be induced through different routes of exposure and are associated with either inhalant symptoms or 2 forms of food allergy Pork-cat syndrome Red meat syndrome Fel d 4 (Lipocalin) cross-react with Can f 6, Equ c 1
  41. 41. Dogs allergens Middleton's 8th edition Environmental assessment and exposure control 2012 : a practice parameter—furry animals Dog allergy appears to be less common than cat allergy as a cause of asthma Airborne Small particles tend to remain airborne for long periods and, when inhaled, can penetrate into the lower airways and trigger asthma symptoms
  42. 42. Can f 1 (Lipocalin) Major dog allergen Size 23-25 kDa Secreted from canine Von Ebner's glands Found in dog hair, dander, and saliva Detectable in all homes with a dog and in 1/3 of homes without dogs 50-90% of patients sensitized to dog have antibodies to Can f 1 Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  43. 43. 288 healthy dogs Levels of Can f 1 on fur vary between breeds, gender, hormonal status, hair length, and according to the presence of seborrhea Ramadour et al. Allergy 2005: 60: 1060–1064.
  44. 44. Breeds (Labrador retriever), sex and seborrhea seem to influence the levels of Can f 1 on fur Ramadour et al. Allergy 2005: 60: 1060–1064.
  45. 45. Can f 2 (Lipocalin) Found in dander and saliva IgE cross-reactivity was demonstrated between Can f 2 and the cat allergen Fel d 4, although they share less than 22% sequence identity >> observed cosensitization to cats and dogs in some individuals Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  46. 46. Can f 3 (Albumin) Albumin seems to be a common cross-sensitizing allergenic component Obviously found in all dogs >> makes it impossible for there to be a completely nonallergenic dog Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  47. 47. Can f 5 (Kallikrein) Similar to prostatic kallikrein Found in up to 70% of patients with dog allergy No patterns of cross-reactivity to allergens from other furry animals Cross-reactivity to human prostate-specific antigen, the major allergen in seminal plasma, has been reported, which suggests that sensitization to Can f 5 could be relevant to seminal fluid allergy Konradsen et al. J Allergy Clin Immunol 2015;135:616-25.
  48. 48. Sensitization (Development of allergen specific IgE) in susceptible individuals If the exposure persists, often leading to manifestations of diseases, such as asthma and rhinitis. Continued exposure to the allergens is likely to exacerbate symptoms and lead to poorer outcomes Environmental assessment and exposure control 2012 : a practice parameter—furry animals Clinical effects of allergen exposure
  49. 49. Threshold level for allergen exposure Cats Dogs Sensitization level (mcg/g.) 1 2 Theshold level (mcg/g.) 8 (Fel d 1) 10 (Can d 1) Almqvist. Clinical Reviews in Allergy & Immunology. Volume 28. 2005. Measurement of cat allergens in settled dust should not be used as a surrogate for airborne exposure (C) Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  50. 50. Early exposure Good or bad ??
  51. 51. For many years, it was assumed that living in a house with a cat increased the risk of allergy In 1999, Hesselmar et al. reported that children who lived in a house with a cat were less likely to be sensitized to cat allergens Konradsen et al. J Allergy Clin Immunol 2015;135:616-25. Individual differences will affect the response to animal exposure, 2 very different mechanisms 1.) IgG4 production : Allergen-specific tolerance 2.) Increased endotoxin or increased bacterial diversity in the home >> effects on the microbiome of the child : not allergen-specific Middleton's 8th edition
  52. 52. Chen et al. J Allergy Clin Immunol 2007;119:1148-55.
  53. 53. Chen et al. J Allergy Clin Immunol 2007;119:1148-55. Higher cat allergen exposures from both parent and children mattresses significantly increased the risk of the development of cat sensitization when the children were 2 years old but showed no effect when the children were 6 years old
  54. 54. Chen et al. J Allergy Clin Immunol 2007;119:1148-55. Age and parental history of allergy were significant risk factors for the development of cat sensitization during childhood.
  55. 55. Pets and Asthma. PLoS One. 2012;7(8):e43214.
  56. 56. Finland All children aged 1–4 yr (N = 4779) Born between 2001 and 2005 Cross-sectional questionnaire data on pet exposure in infancy and physician-diagnosed pet allergies Longitudinally accumulated data on sIgE and skin prick tests indicating allergic sensitization Pyrhonen et al. Pediatr Allergy Immunol 2015: 26: 247–255.
  57. 57. Independently of allergic family history, the incidence of a positive test for either dog or cat allergens was higher and started to rise earlier in children exposed to respective pet allergens at home compared with non-exposed Pyrhonen et al. Pediatr Allergy Immunol 2015: 26: 247–255. Early exposure to dog and cat at home is strongly associated with respective pet allergy and IgE-mediated sensitization to respective pet allergens during the first 4 years of life
  58. 58. 1.) Although exposure to elevated cat allergen Fel d 1 concentrations before 3 months of age may reduce the likelihood of developing cat sensitization, the risk reduction is not sufficient to justify a decision to get a cat to avoid IgE sensitization. (C) 2.) Although exposure to elevated dog allergen Can f 1 concentrations before 3 months of age may reduce the likelihood of developing dog sensitization, the risk reduction is not sufficient to justify a decision to get a dog to avoid IgE sensitization. (C) Environmental assessment and exposure control 2012 : a practice parameter—furry animals Primary prevention
  59. 59. Hypoallergenic pets In 2004, Allerca Lifestyle Pets, a company based out of San Diego, California, began to market “hypoallergenic” cats and dogs Allerca does not claim a 100% success rate for all customers Claims their pets produce lower allergenic quantities of pet dander (eg, Fel d 1 and Can d 1 from cats and dogs, respectively) through gene mutations Eg. Mindeelyn Siberian Cats, Siberian Cat Breeder, Allerca Lifestyle Pets, Kitails Siberian Cattery A. Butt et al. / Ann Allergy Asthma Immunol 108 (2012) 74–76.
  60. 60. “ There was no evidence for differential shedding of allergen by dogs grouped as hypoallergenic ” Nicholas E. et al. Am J Rhinol Allergy 25, 252–256, 2011.
  61. 61. Because 1 or more cat/ dog allergens are present in all cats/ dogs, patients should not be advised that it is safe to obtain a nonallergenic cat/ dog (C) >> No studies have shown conclusively that cats can be hypoallergenic >> Hypoallergenic dogs were no less allergenic than regular breeds Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  62. 62. Diagnosis History of pet exposure Skin prick test / Specific IgE Challenge/ provocation test Environmental assessment and exposure control 2012 : a practice parameter—furry animals Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  63. 63. Environmental assessment and exposure control 2012 : a practice parameter—furry animals Dog epithelium 1:20 (W/V) Cat hair 10,000 BAU/ml
  64. 64. Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  65. 65. Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  66. 66. Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  67. 67. Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  68. 68. This study clearly supports the value of SPTs and RASTs in the diagnosis of cat allergy. Although not perfect, a positive result with these 2 tests is most often indicative of a true cat allergy; a negative result, especially for SPTs, rules out most cases of cat allergy. IDSTs appear considerably less diagnostically useful. Wood et al. J Allergy Clin Immunol 1999;103:773-9.
  69. 69. Environment control
  70. 70. Environmental assessment and exposure control 2012 : a practice parameter—furry animals 1.) Avoidance/ Removing pets from home Avoidance is the most effective way to manage cat and dog allergy. Patients should be advised to consider removing the cat or dog from the environment, if present, to improve respiratory health. (A)
  71. 71. By the 20 th week after cat removal, levels 8/15 homes were within or very close to the upper 95% confidence limit of the 18 control homes without cats Median Fel d 1 content reached that level at approximately 23 weeks after cat removal Wood et al. J Allergy Clin Immunol 1989;83:730-4. 20-24 weeks
  72. 72. Environmental assessment and exposure control 2012 : a practice parameter—furry animals 2.) Reduce exposure to allergens To reduce exposure to cat allergens with the cat still living in the house, a combination of measures, such as removing reservoirs, keeping the cat out of the bedroom, washing the cat, air cleaning with a HEPA room air cleaner, improving ventilation, and mattress and pillow covers, may be helpful. (C)
  73. 73. Environmental assessment and exposure control 2012 : a practice parameter—furry animals 2.1) Removing reservoirs Carpeting and bedding serve as significant reservoirs, frequent vacuuming or ideally carpet removal should be considered (C) To reduce transport of cat allergen, people should consider changing their clothes when traveling from a high cat allergen environment to a low cat allergen environment (C) Long-term regular use of high-efficiency or central vacuum cleaners is associated with reduced exposure to Fel d 1 and Can f 1 in homes with cats or dogs living in them, although the health effects are uncertain. (B)
  74. 74. Mattress encasings - Some woven microfiber bed encasings, generally those with a mean pore size of 6 micron or less, block cat allergen from penetrating the fabric though the respiratory health benefit from their use is unclear. (C) - Nonwoven microfiber encasings collect allergen on their surface over time, including cat and mite allergens. Because they cannot be washed, they are unsuitable for allergen avoidance. (C) Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  75. 75. Environmental assessment and exposure control 2012 : a practice parameter—furry animals 2.2) Removing allergens from pets Washing cats or dogs at least weekly can reduce airborne cat Fel d 1 or dog Can f 1; however, the clinical benefit is yet to be proven and the effect of washing is not sustained. (B)
  76. 76. Suggested that cats should be bathed in tap water or pet shampoo for at least 3 minutes to solubilize Fel d 1 Avner et at. J Allergy Clin Immunol 1997;100:307-12.
  77. 77. Immersion of cats in water for 3 minutes produced a highly significant reduction in airborne allergen 3 hours later, but the quantity of allergen becoming airborne from the cat did not remain low 1 week later Avner et at. J Allergy Clin Immunol 1997;100:307-12.
  78. 78. Environmental assessment and exposure control 2012 : a practice parameter—furry animals HEPA air cleaners run continuously over time can reduce exposure to dog and cat allergen concentrations, but the clinical benefits are unknown. (B) 2.3) Air filtration 2.4) Use of dry heat Dog and cat allergens are relatively stable to dry heat so dry heat should not be used specifically to reduce exposure. (C)
  79. 79. Environmental assessment and exposure control 2012 : a practice parameter—furry animals 2.5) Chemical treatments Chemical treatments, such as tannic acid, can be applied to carpet to give short-term reduction of cat allergen, but this is not sustained and there is no evidence that it improves respiratory health. (C) Use of hypochlorite bleach to denature indoor allergens can reduce allergen exposure, improve quality of life, and reduce the likelihood of developing atopy, but it can also lead to increased respiratory symptoms in individuals using it. (C)
  80. 80. Sufficient control of exposure to cat allergens to improve health requires a combination of measures, such as removing reservoirs, keeping the cat out of the bedroom, washing the cat, air cleaning with a HEPA room air cleaner, improving ventilation, and mattress and pillow covers. (C) Combination measures Environmental assessment and exposure control 2012 : a practice parameter—furry animals
  81. 81. SHARMA et al. Pediatr Clin N Am 54 (2007) 103–120.
  82. 82. Middleton's 8th edition Environmental assessment and exposure control 2012 : a practice parameter—furry animals Cat hair extracted for 3 minutes with tap water or pet shampoo for 3 minutes can remove a mean of 200 g of Fel d 1 per gram of hair
  83. 83. Immunotherapy
  84. 84. Exposure to both dog and cat allergen has been shown to be ubiquitous and can occur even without an animal in the home, making avoidance even more difficult The major allergen content of cat extracts is relatively low, requiring larger amounts to be given than for pollens or house dust mite The major allergen content of most dog extracts is too low to allow effective dosing, even with undiluted manufacturers' extracts Allergen immunotherapy 2011 : a practice parameter third update
  85. 85. The first randomized double-blind placebo-controlled trial using SCIT for cat-induced asthma was reported in 1984. - received SCIT with purified cat pelt allergen : 9 patients received placebo : 8 patients Results : The treatment group was shown - delayed onset of ocular and respiratory symptoms with cat exposure - decreased magnitude of SPT reactivity to cats - decreased methacholine responsiveness - increased serum IgG to cat allergen Ohman JL Jr , et al. J Allergy Clin Immunol 74:230 –239, 1984.
  86. 86. Lilja et al. J Allergy Clin Immunol 1989;83 :37-44.
  87. 87. Alvarez-Cuesta et al. J Allergy Clin Immunol 1994;93:556-66. " Standardized cat extract IT "
  88. 88. Allergen immunotherapy 2011 : a practice parameter third update
  89. 89. SCIT has shown real benefit in cat-allergic patients with allergic asthma and allergic rhinoconjunctivitis. The data for dog are less robust SLIT remain experimental Morris Ling, et al.Allergy Asthma Proc 31:385–391, 2010. Dog epithelium 1:10 (W/V) Cat hair 10,000 BAU/ml
  90. 90. Thank you

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