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House dust mite
Allergy
Lalita Tearprasert; M.D.
Scope
• Introduction
• HDM allergens and Cross-reactivity
• HDM & Respiratory allergic diseases
• Mechanisms of HDM allerg...
Introduction
• Major perennial indoor allergen cause Asthma, AR, AD
• 50 – 85% of asthmatics are typically HDM allergic
• ...
Phylum Arthropoda
Domestic mite:
Any species of mite found in house
Dust mite:
Family Pyroglyphidae
- Dermatophagoides
- E...
J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507.
Domestic
mite
Family Pyroglyphidae
• Dermatophagoides (Subfamily Dermatophagoidinae)
- Dermatophagoides pteronyssinus (Dp)/ European HDM...
• D. pteronyssinus (Dp) tends to be most abundant.
• Only a few countries have either predominantly D. pteronyssinus or D....
In Thailand
N.Malainual et al. Clinical and Expiramental Allergy ,1995, Volume 25, 554-560.
• Eight-legged, Sightless
• 0.3 mm. in length
• Absorbing water through Hygroscopic substance
extrude from leg joints
• Ha...
Life cycle- Egg to adult : 1 month
- Adult living an additional 1-3 months.
- Adult females lay up to 40-80 eggs
• Temperature : 65-80°F (20-25°C)
• Relative humidity (RH) : 70-75%
>> carpets, sofas, mattresses, or clothing
Optimum gro...
• Environmental factors of temperature and RH is reflected in seasonal fluctuations
in dust mite numbers and allergen leve...
HDM allergens
Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411.
• Mite allergens are present in mite bodies, secreti...
• Airborne mite allergen is detected only during or shortly after
disturbance of dust. Fell rapidly after disturbance.
• L...
Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469.
• Exposure to mite allergens is in the form of fecal ...
Mite Allergen Group
M. RAULF et al. Allergo J Int 2015; 24: 68–80. Fernández-Caldas et al.
Chem Immunol Allergy, 2014, vol...
• Allergens from mites include commonly encountered functions
of allergens from a wide variety of sources
- Proteases (Gro...
Group 1
Caldereon, et al. J Allergy Clin Immunol. July 2015; 38-48
Schulz O. et al. J. Exp. Med. 1998, 271-275
Cysteine pr...
• Group 3 : Trypsin-like enzyme
- also found in insect venoms
- Der p 3 quite similar to the cockroach Bla g 10
• Group 6 ...
• Innate immune: TLR4 (on DCs, airway
epithelium, and airway smooth muscle cells)
bind endotoxin
• Adaptive immune: Promot...
• Occurs because of shared similar or identical IgE-binding epitopes
• Der p highly cross-reactivity with Der f
- Group 2 ...
Group10
Tropomyosin
• Muscle protein
• coiled- coil structure, two
parallel alpha-helical
• Location: Muscle
• Der p10, De...
• Shrimp (Pen i 1, Pen a 1, Met e 1) identity 81-90%
• Cockroachs (Per a 7, Bla g 7) identity 80%
• Other Crustacean
- Cra...
Threshold level
• Most studies accept
- Sensitization threshold level 2 μg/g. of dust (100 mites/g.)
- Threshold levels fo...
1. Two-side monoclonal antibody (mAb) based enzyme
immunoassay (ELISA) -- --> Gold standard
- most common available : Der ...
• Environmental assessment and exposure control of dust mites:
a practice parameter 2013
• Advise patients to minimize exp...
Sporik R et al. N Engl J Med (1990);323: 502-7.
Active asthma was very strongly associated with
both atopy & sensitivity t...
Casas et al.European journal of allergy and Clinical Immunology.Allergy 70 (2015); 820-827.
Early life exposure plays a ro...
Lodge,et al.J Allergy Clin Immunol 2011;128:782-8.
• Birth cohort of 620 children
oversampled for familial allergy
• SPTs ...
Lodge,et al.J Allergy Clin Immunol 2011;128:782-8.
HDM sensitization was associated with current wheeze at age 12 years
Danansuriya et al. World Allergy Organization Journal (2015) 8:19
• Students with current asthma
were having13 times
highe...
• House dust mite and the cockroach are
the most important aeroallergen
sensitizers in Thai allergic rhinitis
patients, si...
• 2 Main route
1.) Innate immune system --> Epithelial cells, Dendritic cells
2.) CD4+ TH2 cells induce and IgE-dependent ...
Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411.
Innate immune system : Epithelial cell
Group 1(cystein protease): ...
Potential enhancement of the allergic response by
HDM
Caldereon, et al. J Allergy Clin Immunol. July 2015;136:38-48.
Der p...
• Skin testing and/or specific IgE
• Nasal provocation testing (NPT) : perennial AR due to HDM when the
patient history pr...
• D. farinae ,D. pteronyssinus, Mite mix extracts are standardized.
• Commercially available in many country ex. the Unite...
1. ) Environment control
- Recommend avoidance for SPT positive to HDM
2. ) Immunotherapy - Subcutaneous (SCIT), Sublingua...
Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469.
Environmental control
Avoidance
1.) Physical
2.) Chem...
• A special mite-impermeable
membrane was used in PE and CE
group
• Regular bedsheets were applied to
all groups
• PE grou...
• The ideal mite cover should have at least 2
important characteristics
1.) block the leakage of mite
allergens from the i...
• Environmental assessment and exposure control of dust mites: a
practice parameter 2013
- Woven microfiber fabrics with a...
Remove carpets, stuffed animals, and clutter from bedroom
• Removing carpets is more effective in the long term than any c...
Wash bedding regularly 130° F
• 130°F (55°C) can kill mites and allergen removed by washing generally reappears within 1
m...
• Vacuum weekly (wearing a mask) using vacuum cleaner with a double-
thickness bag or a high-efficiency particulate air (H...
Reduce humidity
• Reduce humidity below 45% relative humidity (or 6 g H2O/ kg air)
• Environmental assessment and exposure...
Reduce humidity
• Remove excessive : Using a dehumidifier and/or air conditioning
- Dehumidifier needs to be emptied regul...
• killing mites
• Benzyl benzoate Moist powder and foam.
- The active powder kills 90% of mites in culture within 12 hours...
• Protein-denaturing agent
• Reduce allergen levels in house dust : 1% and 3% solutions
• Does not kill mites, so the effe...
Immunotherapy
Akkoc et al. Allergy Asthma Immunol Res. 2011 January;3(1):11-20.
• Recommend 3 to 5 years
• Effective dose
- SCIT : 7 mg of Der p 1 per dose for European extracts
500-2,000 AU per dose fo...
• Retrospective study
• 39 patients (23 boys,16 girls)
• Children with asthma and rhinitis who
were allergic to house dust...
Cingi C. et al. Eur Arch Otorhinolaryngol. 2014.
• 186 patients with AR who had positive SPT for HDMs
• Administered SLIT ...
HUI Y. et al. Expiramental and therapeutic medicine 7: 630-634, 2014.
• 90 asthmatic children (with or without
allergic rh...
In thailand
• A double blind, self-controlled study between the
SMAV and standardized commercial mite allergen
vaccine
• 1...
Thank you
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House dust mite allergy

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Presented by Lalita Tearprasert, MD.

August 07, 2015

Published in: Health & Medicine

House dust mite allergy

  1. 1. House dust mite Allergy Lalita Tearprasert; M.D.
  2. 2. Scope • Introduction • HDM allergens and Cross-reactivity • HDM & Respiratory allergic diseases • Mechanisms of HDM allergen induced sensitization • Diagnosis of HDM Allergy • Preventive and Therapeutic Approaches for HDM Allergy
  3. 3. Introduction • Major perennial indoor allergen cause Asthma, AR, AD • 50 – 85% of asthmatics are typically HDM allergic • Prevalence data for HDM allergen sensitization vary from 65 to130 million persons (1-2%) in the general population worldwide • Geographic variation • In1967, Spieksma and Voorhorst established that the dust mite, Dermatophagoides pteronyssinus, was an important source of house dust allergens in the Netherland Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411.
  4. 4. Phylum Arthropoda Domestic mite: Any species of mite found in house Dust mite: Family Pyroglyphidae - Dermatophagoides - Euroglyphus Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Storage mite(flour,grain, barn, hay): Family Acaridae & Glycyphagidae (Tropical mite : Blomia tropicalis)
  5. 5. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Domestic mite
  6. 6. Family Pyroglyphidae • Dermatophagoides (Subfamily Dermatophagoidinae) - Dermatophagoides pteronyssinus (Dp)/ European HDM - Dermatophagoides farinae (Df)/ American HDM • Euroglyphus (Subfamily Pyroglyphinae) - Euroglyphus maynei (Em) >> England, Europe, the southern United state >> Em frequently co-inhabits with Dp and Df in some geographical areas >> Many patients sensitive Dp, Df are also sensitive to Em >> Extracts of Em for diagnosis and immunotherapy are not commercially available House dust mite The two most common HDM species worldwide : Dp, Df Fernández-Caldas et al. Chem Immunol Allergy, 2014, vol 100, 234–242. Morgan S. et al.Int Arch Allergy Immunol 2015;166:267–272.
  7. 7. • D. pteronyssinus (Dp) tends to be most abundant. • Only a few countries have either predominantly D. pteronyssinus or D. farinae. - Australia, New Zealand, England and Mauritius have D. pteronyssinus with few other HDM - Singapore has a bias to D. pteronyssinus but with B. tropicalis - Most of South Korea has a bias to D. farinae especially in the northwest - Italy also has D. farinae -biased • In Asia; Singapore, Malaysia, Hong Kong and the Phillipines have D.pteronyssinus as the dominant pyroglyphid HDM. Thailand and Taiwan and have more D. pteronyssinus than D. farinae Distribution of Dermatophagoides species Wayne R Thomas. Asian Pac J Allergy Immunol 2010;28:211-24.
  8. 8. In Thailand N.Malainual et al. Clinical and Expiramental Allergy ,1995, Volume 25, 554-560.
  9. 9. • Eight-legged, Sightless • 0.3 mm. in length • Absorbing water through Hygroscopic substance extrude from leg joints • Habitat with 3 key macromolecules derived from organic debris - keratin (human skin scales) --> food source - cellulose (textile fibers) - chitin (fungal hyphae and mite cuticles) Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Caldereon, et al. J Allergy Clin Immunol. July 2015;136:38-48. • Excrete fecal particles - contain allergenic digestive enzyme - chitinous peritrophic membrane (not waterproof) - size 10-35 micron (similar to pollen grain) - carry allergen 0.2 ng - airborne and easily inhaled
  10. 10. Life cycle- Egg to adult : 1 month - Adult living an additional 1-3 months. - Adult females lay up to 40-80 eggs
  11. 11. • Temperature : 65-80°F (20-25°C) • Relative humidity (RH) : 70-75% >> carpets, sofas, mattresses, or clothing Optimum growth condition Thomas A.E. Plattes-Mills.Middleton's Allergy 8th Edition. 453-469. Yu SJ, et al.Asia Pac Allergy 2014;4:241-252.
  12. 12. • Environmental factors of temperature and RH is reflected in seasonal fluctuations in dust mite numbers and allergen levels in different parts of the world. • Summer is warm and dump so mite population can expand. • The most important facilitative factor for mite growth is RH. - Once humidity decreases below 50%, mite proliferation and survival is decreased. - Mites can survive for weeks before they die. - As humidity falls, it may take months for mites to die and longer for allergen levels to decrease in carpets, sofas, or mattresses. - An elevated RH for as briefly as little as 1.5 hours per day (cooking, bathing), the mite can survive. 2 to 3 hours per day, mites can reproduce.
  13. 13. HDM allergens Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411. • Mite allergens are present in mite bodies, secretion and excretion • Fecal particles contain the greatest proportion of mite allergen
  14. 14. • Airborne mite allergen is detected only during or shortly after disturbance of dust. Fell rapidly after disturbance. • Little or no airborne allergen (e.g., less than 1 ng/m3) is present in undisturbed conditions. • Indicate that mite allergen is predominantly airborne on particles greater than 10 µm in diameter. • Fecal particles become airborne and easily inhaled. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507.
  15. 15. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. • Exposure to mite allergens is in the form of fecal particles contain - Mite-derived proteins - Endotoxin derived from bacteria >> potent TLR-4 agonist - Mite DNA and bacterial DNA (unmethylated) >> activate TLR-9. - Chitin peritrophic membrane >> Chitin and its breakdown products can act on TLR-2 and dectin-1 Potential adjuvants
  16. 16. Mite Allergen Group M. RAULF et al. Allergo J Int 2015; 24: 68–80. Fernández-Caldas et al. Chem Immunol Allergy, 2014, vol 100, 234–242. 33 groups Major allergens (frequency of patients sensitized and amount of specific IgE) - Group 1 (Der p 1 and Der f 1) - Group 2 (Der p 2 and Der f 2)
  17. 17. • Allergens from mites include commonly encountered functions of allergens from a wide variety of sources - Proteases (Group1, 3, 6, 9, 20) - Lipid-binding proteins (Group 2, 7, 13, 14) - Contractile proteins (Group 10, 11, 16, 17, 24) - Glycosidases and carbohydrate-binding proteins (Group 4, 12, 15, 18, 23) - Glutathione S-transferase (Group 8) - Unidentified function • Most mite allergens are enzymes J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Rubaba Hamid Shafique, M.Phil et al. Allergy Rhinol 3: 74–90, 2012. Mite Allergen functions
  18. 18. Group 1 Caldereon, et al. J Allergy Clin Immunol. July 2015; 38-48 Schulz O. et al. J. Exp. Med. 1998, 271-275 Cysteine proteases - Destroy the epithelial tight junctions - Innate immune response :recognized by PAR-2 and TLRs --> PAMPs - Adaptive immune : Promote Th2 - Activating mast cells independently of IgE • Glycoprotein 25 kDa, Heat-labile • Peptidase enzyme/ Proteolytic enzyme (Identity with plant enzyme papain) • Location: Gut • Der p1, Der f1 • Der p 1: significant role in IgE antibody responses 1.) Cleavage of CD23 (FCeRII on B cells) ----> IgE 2.) Cleavage of CD25 (IL-2R on T cells) ----> Th2 response
  19. 19. • Group 3 : Trypsin-like enzyme - also found in insect venoms - Der p 3 quite similar to the cockroach Bla g 10 • Group 6 : Chymotrypsin • Group 9 : Collagenolytic serine protease Group 3,6,9 Serine proteases • Trypsin - Destroy the epithelial tight junctions - Trigger PAR-2 ---> results in the initiation of multiple G-protein coupled signaling cascades - Promote Th2 J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507.
  20. 20. • Innate immune: TLR4 (on DCs, airway epithelium, and airway smooth muscle cells) bind endotoxin • Adaptive immune: Promotion of TH2 polarization and inflammatory cell recruitment Group 2 • Glycoprotein 15 kDa, Heat-stable • Molecular mimicry of MD-2 protein (lymphocyte antigen 96) • Lipid-transfer or lipid-carrying proteins • Location: Intracellular • Der p2, Der f2 MD-2 like lipid-binding protein Caldereon, et al. J Allergy Clin Immunol. July 2015; 38-48. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Associated with Oral mite syndrome
  21. 21. • Occurs because of shared similar or identical IgE-binding epitopes • Der p highly cross-reactivity with Der f - Group 2 allergens are very similar to each other in structure, with greater than 90% sequence homology, indeed, no mAb assays currently available can distinguish Der p 2 from Der f 2 • B. tropicalis cross-react partially with other dust mites >> designated Blo t 5 because it has sequence homology with Der p 5 G. Reese et al.Int Arch Allergy Immunol 1999;119:247–258. Thomas A.E. Plattes-Mills.Middleton's Allergy 8th Edition. 453-469. Cross-reactivity
  22. 22. Group10 Tropomyosin • Muscle protein • coiled- coil structure, two parallel alpha-helical • Location: Muscle • Der p10, Der f10 • Invertebrates - Crustaceans (shrimp, lobster, crab, craw-fish) - Arachnids (house dust mites) - Insects (cockroaches) - Mollusks (e.g. squid) • 5% to 15% of patients who are highly sensitized to dust mite also are sensitized to crustaceans G. Reese et al.Int Arch Allergy Immunol 1999;119:247–258. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. • Found - Invertebrate >> Allergic - Vertebrate >> Non-allergic
  23. 23. • Shrimp (Pen i 1, Pen a 1, Met e 1) identity 81-90% • Cockroachs (Per a 7, Bla g 7) identity 80% • Other Crustacean - Crab: Cha f 1 - Lobster: Pan s 1, Hom a 1 identity 81-90% • Mollusk (Cra g 1, Tur c 1, Tod p 1) • Helminth (Ascaris, Filaria and Anisakis simplex) G. Reese et al.Int Arch Allergy Immunol 1999;119:247–258 Tropomyosin • Der p10, Der f10
  24. 24. Threshold level • Most studies accept - Sensitization threshold level 2 μg/g. of dust (100 mites/g.) - Threshold levels for for developing symptoms in already sensitized individuals 10 μg/g. of dust (500 mites/g.) - For nonallergic children higher threshold level 20 μg/g. of dust World Health Organization (WHO).Bull World Health Organ 1988;66:769-80. HDM & Respiratory allergic diseases
  25. 25. 1. Two-side monoclonal antibody (mAb) based enzyme immunoassay (ELISA) -- --> Gold standard - most common available : Der p1, Der f1/ Der p2, Der f2/ Blo t5 2. Guanine (the major nitrogenous excretory product of arachnids) 3. Mite count Methods of estimating dust-mite allergens A. Custovic.Allergy 1998; 53 (Suppl 48): 71-76
  26. 26. • Environmental assessment and exposure control of dust mites: a practice parameter 2013 • Advise patients to minimize exposure of susceptible children to dust mite allergens to decrease their risk of developing mite-specific IgE. Because intermittent exposure to mite allergens can lead to sensitization. (Strength of recommendation: strong, A evidence) • Advise patients to minimize exposure of dust mite sensitized children to dust mite allergens to decrease their risk of developing asthma and possibly rhinitis. (Strength of recommendation: strong, A evidence) Sensitization & Development respiratory disease
  27. 27. Sporik R et al. N Engl J Med (1990);323: 502-7. Active asthma was very strongly associated with both atopy & sensitivity to HDM Significant relation between high levels of expose and early onset of wheezing (P=0.001)
  28. 28. Casas et al.European journal of allergy and Clinical Immunology.Allergy 70 (2015); 820-827. Early life exposure plays a role in the development of sensitization
  29. 29. Lodge,et al.J Allergy Clin Immunol 2011;128:782-8. • Birth cohort of 620 children oversampled for familial allergy • SPTs to 6 allergens at ages 6, 12, and 24 months • Wheeze and eczema were recorded during the first 2 years • Current wheeze was recorded at age 12 years • New-onset sensitization by 2 years or sensitization at both 1 and 2 years were both strong predictors of wheeze at age 12 years
  30. 30. Lodge,et al.J Allergy Clin Immunol 2011;128:782-8. HDM sensitization was associated with current wheeze at age 12 years
  31. 31. Danansuriya et al. World Allergy Organization Journal (2015) 8:19 • Students with current asthma were having13 times higher risk of atopy to HDM compared to their healthy siblings
  32. 32. • House dust mite and the cockroach are the most important aeroallergen sensitizers in Thai allergic rhinitis patients, since more than half the patients were skin test positive to the house dust mite and the cockroach. • 85% of mite-sensitive patients were skin test positive to both species of Dermatophagoides, indicating substantial cross reactivity. Pumhirun et al.Asian Pac J Allergy Immunol (1997) 15: 183-185
  33. 33. • 2 Main route 1.) Innate immune system --> Epithelial cells, Dendritic cells 2.) CD4+ TH2 cells induce and IgE-dependent allergic response Mechanism of HDM allergen induced sensitization Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411. Innate epithelial cytokines Dendritic cells Th2
  34. 34. Gregory and Lloyd.Trends Immunol. 2011; 32(9): 402–411. Innate immune system : Epithelial cell Group 1(cystein protease): PAR-2 Group 2 (MD-2 like LBP): TLR-4 Endotoxin : TLR-4 B-glycan : Dectin-1 Chitin : TLR-2, Dectin-1 Mite&Bac. DNA : TLR-9
  35. 35. Potential enhancement of the allergic response by HDM Caldereon, et al. J Allergy Clin Immunol. July 2015;136:38-48. Der p 1: significant role in IgE antibody responses 1.) Cleavage of CD23 (FCeRII on B cells) ----> IgE 2.) Cleavage of CD25 (IL-2R on T cells) ----> Th2 response Group 1(cystein protease): PAR-2 Group 2 (MD-2 like LBP): TLR-4 Endotoxin : TLR-4 B-glycan : Dectin-1 Chitin : TLR-2, Dectin-1 Mite&Bac. DNA : TLR-9
  36. 36. • Skin testing and/or specific IgE • Nasal provocation testing (NPT) : perennial AR due to HDM when the patient history provides inconclusive information Diagnosis of HDM allergy M. RAULF et al. Allergo J Int 2015; 24: 68–80
  37. 37. • D. farinae ,D. pteronyssinus, Mite mix extracts are standardized. • Commercially available in many country ex. the United States, Europe, Maxico. • Content of extracts varies depending on whether purified mite bodies or total spent culture is used as the source material - Mite bodies greater than 99% purity and are almost exclusively used in the United States >> 40 µg/mL of Der p 1 and 30 µg/mL of Der p 2 - Spent cultures containing adult mites, eggs, larvae, fecal particles, and culture medium are often used in Europe >> at least 10 times more group 1 than group 2 Dust mite extracts Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-481. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507.
  38. 38. 1. ) Environment control - Recommend avoidance for SPT positive to HDM 2. ) Immunotherapy - Subcutaneous (SCIT), Sublingual (SLIT) Preventive and Therapeutic Approaches Fernández-Caldas et al.History of Allergy. Chem Immunol Allergy, 2014, vol 100, 234–242. Thomas A.E. Plattes-Mills.Middleton's Allergy 8th Edition. 453-469.
  39. 39. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Environmental control Avoidance 1.) Physical 2.) Chemical
  40. 40. • A special mite-impermeable membrane was used in PE and CE group • Regular bedsheets were applied to all groups • PE group : mattresses were encased on tops and sides only CE group : complete mattress encasement was undertaken • Mattress encasing with a special membrane was highly efficacious in the reduction of mite allergen (90%). • Complete mattress encasing in a tropical environment does not offer any advantage over partial encasing in the reduction of mite allergen Vichyanond et al. Allergy 1999, 54, 736-741. Cover mattresses and pillows with impermeable cover
  41. 41. • The ideal mite cover should have at least 2 important characteristics 1.) block the leakage of mite allergens from the inside of the bedding 2.) prevent mites from penetrating through the covers in either direction Mahakittikun et al. J Allergy Clin Immunol 2006;118:1164-8. Cover mattresses and pillows with impermeable cover
  42. 42. • Environmental assessment and exposure control of dust mites: a practice parameter 2013 - Woven microfiber fabrics with a mean pore size smaller than 10 micron can effectively block passage of Der p 1 (Strong, B evidence) - Dust mite allergens (Der f 1 and Der p 1) were decreased to below detectable limits by fabrics with a pore size smaller than 10 micron J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Cover mattresses and pillows with impermeable cover
  43. 43. Remove carpets, stuffed animals, and clutter from bedroom • Removing carpets is more effective in the long term than any currently available carpet cleaning measure. • Designing the house with polished floors and wooden or vinyl or leather furniture, to limit the sites where mites can grow and to reduce dust collectors so as to make cleaning easier. • Environmental assessment and exposure control of dust mites: a practice parameter 2013 • The most effective way to manage reservoirs of mite allergens is to remove them completely from the environment. That means removing carpets, drapes, and upholstered furniture and sealing mattresses, box springs, and pillows in mite-impermeable covers J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469.
  44. 44. Wash bedding regularly 130° F • 130°F (55°C) can kill mites and allergen removed by washing generally reappears within 1 month • Washing bedding at 130°F (55°C) once weekly is effective • Environmental assessment and exposure control of dust mites: a practice parameter 2013 - Most mites that are killed in the washing process die by drowning. Although higher temperature kills slightly more mites. - There is evidence that temperatures lower than 130°F are adequate, high temperature is not necessary. - Home hot water should be kept below 120°F prevent danger to children. - Wash bedding weekly in warm water, without aiming for a specific and potentially dangerous temperature. This will remove most, not all, mites and mite allergens. Clothing also should be washed after use. (strong, B evidence) J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469.
  45. 45. • Vacuum weekly (wearing a mask) using vacuum cleaner with a double- thickness bag or a high-efficiency particulate air (HEPA) filter. • Regular (at least weekly) vacuuming is essential for preventing buildup of mite allergens in homes with carpets. • Vacuuming does not remove all live mites, mite allergens in the form of fecal particles can be removed. Vacuuming Vacuuming J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469.
  46. 46. Reduce humidity • Reduce humidity below 45% relative humidity (or 6 g H2O/ kg air) • Environmental assessment and exposure control of dust mites: a practice parameter 2013 - Advise patients that relative humidity in the home should be kept between 35% and 50% to decrease the growth of dust mites (Strong, B evidence) - Encourage dust mite-allergic patients to obtain and use a hygrometer to measure humidity in their home. (Strong, D evidence) J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507
  47. 47. Reduce humidity • Remove excessive : Using a dehumidifier and/or air conditioning - Dehumidifier needs to be emptied regularly or set to drain continuously, and it should be located in areas where dampness is likely to occur. - Air conditioners need to run long enough to remove sufficient moisture from the air to decrease RH. J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507
  48. 48. • killing mites • Benzyl benzoate Moist powder and foam. - The active powder kills 90% of mites in culture within 12 hours and 100% in 24 hours - Reapplied at 2-3 month intervals • Environmental assessment and exposure control of dust mites: a practice parameter 2013 - Acaricides are not recommended for use on mattresses, particularly given the likelihood of exposure to the chemical - Limited efficacy at decreasing allergen levels (moderate, B evidence) Acaricides Ex. Benzyl benzoate,pyrethroids, natamycin (an antifungal), pirimiphosmethyl J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Treat carpets with benzyl benzoate or tannic acid
  49. 49. • Protein-denaturing agent • Reduce allergen levels in house dust : 1% and 3% solutions • Does not kill mites, so the effect can only be temporary. Reapplied at 1-2 week intervals • TA was very effective at reducing mite allergen levels in dust, though it required up to 4 hours to exert its full effect. Tannic acid Woodfolk et al. Allergy Clin lmmunol. Volume 94, Number 1, 1994, 19-26. Thomas A.E. Plattes-Mills. Middleton's Allergy 8th Edition. 453-469. Treat carpets with benzyl benzoate or tannic acid • Environmental assessment and exposure control of dust mites: a practice parameter 2013 - Do not recommend tannic acid for decreasing mite allergens in carpet dust because it is only marginally effective : concentrations of tannic acid as low as 0.1% were found to inhibit the ELISA assays (Moderate, C evidence)
  50. 50. Immunotherapy Akkoc et al. Allergy Asthma Immunol Res. 2011 January;3(1):11-20.
  51. 51. • Recommend 3 to 5 years • Effective dose - SCIT : 7 mg of Der p 1 per dose for European extracts 500-2,000 AU per dose for US extracts (US >> Der p1:Der p2 = 1:1, Europe >> Der p1:Der p2 = 10:1) - SLIT : 4,200 AU containing approximately 70 mg of Der f 1 given daily • Frequency of administration once maintenance is reached - SCIT : Ranged from weekly to monthly - SLIT : Daily to 3 times per week • No evidence to support giving lower doses more frequently or higher doses less frequently to obtain similar efficacy • Dust mite extracts are compatible with pollen and animal dander extracts and can be mixed with fungal and cockroach extracts provided they are kept in glycerin at a concentration of at least 10% Immunotherapy J. Portnoy et al. / Ann Allergy Asthma Immunol 111 (2013) 465-507 Practice parameter 2013
  52. 52. • Retrospective study • 39 patients (23 boys,16 girls) • Children with asthma and rhinitis who were allergic to house dust mite • 3 years of SLIT with 50 % Der p and 50 % Der f in a standardized extract Conclusion • SLIT is effective in children who have allergic airway disease which cannot be controlled effectively with allergen avoidance measures only Y Nuhoglu, et al. J Investig Allergol Clin Immunol 2007; Vol. 17(6): 375-378.
  53. 53. Cingi C. et al. Eur Arch Otorhinolaryngol. 2014. • 186 patients with AR who had positive SPT for HDMs • Administered SLIT using for 1 year • Evaluation of the patients regarding - symptom scores - clinical findings - Rhinitis Quality of Life Questionnaire (RQLQ) • At baseline, 6 and 12 months of therapy.
  54. 54. HUI Y. et al. Expiramental and therapeutic medicine 7: 630-634, 2014. • 90 asthmatic children (with or without allergic rhinitis) with a mild to moderate HDM allergy (aged, 5-14 years) were recruited • SCIT combined with standardized management (ICS) for 36 months. • Suggest that long-term SCIT may alleviate asthma symptoms and reduce the required dose of ICS.
  55. 55. In thailand • A double blind, self-controlled study between the SMAV and standardized commercial mite allergen vaccine • 17 normal Thai adult males and non-pregnant or non- lactating females aged 18-60 years Result - No significant difference in wheal and flare diameter - Significant correlation between wheal diameter - Suggested that SMAV could be used for SPT instead of using the more expensive imported commercial vaccine Visitsunthorn, et al.ASIAN PACIFIC JOURNAL OF ALLERGY AND IMMUNOLOGY (2010) 28: 41-45.
  56. 56. Thank you

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