title: High rate of house dust mite sensitization in a shrimp allergic southern Ontario population.
abstract: BACKGROUND
  Shrimp and house dust mite (HDM) allergies are common in Canadians. Often, both of these allergies occur in the same patient. This may be due to homology of tropomyosin or other potentially shared proteins. The aim of our study was to assess the frequency of house dust mite sensitization in a shrimp allergic Canadian population.
  
  
  METHODS
  We undertook a retrospective chart review of shrimp allergic patients at an outpatient allergy clinic in Kitchener, Ontario, Canada. Our primary endpoint was to assess for presence of HDM sensitization in this population. Patients were categorized into approximate quartiles. We assessed the severity of the shrimp reactions, correlated shrimp skin test size to HDM skin test size, and measured the proportion of patients with atopic symptoms.
  
  
  RESULTS
  We identified 95 shrimp allergic patients who were tested for house dust mite. 86 (90.5%) of these patients had a positive skin test to HDM. Patients with a shrimp skin test ≥5 mm were 5.31 times (95% CI, 1.55-18.14; p = 0.008) more likely to exhibit a dust mite skin test ≥5 mm than patients with a shrimp skin test <5 mm. The odds of a patient with a shrimp skin test between 10 and 18 mm having a larger HDM skin test were 3.93 times (95% CI 1.03-14.98, p = 0.045) the odds for a patient with a shrimp skin test size between 3 and 4 mm. We did not find a correlation between shrimp skin test size and shrimp reaction symptom grade (p = 0.301).
  
  
  CONCLUSIONS
  In our Canadian patients, we found a large majority of shrimp allergic patients to be sensitized to HDM. We found that patients with a large skin test to shrimp were more likely to have a large skin test to HDM compared to those patients with a small skin test to shrimp. We did not find a correlation between shrimp skin test size and shrimp reaction symptom severity. Most of these patients had symptoms of rhinitis and/or asthma that may have been caused by house dust mite allergy.
authors.affiliation: Division of Clinical Immunology and Allergy, Department of Medicine Michael D. DeGroote School of Medicine, McMaster University, Hamilton, ON Canada.
authors.forename: Lana
authors.identifier: 0000-0002-1557-6673
authors.initials: L
authors.lastname: Rosenfield
authors.affiliation: Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON Canada.
authors.forename: Michael William
authors.initials: MW
authors.lastname: Tsoulis
authors.affiliation: Faculty of Science, University of Waterloo, Waterloo, ON Canada.
authors.forename: Kirolos
authors.initials: K
authors.lastname: Milio
authors.affiliation: Grandriver Allergy, Kitchener, ON Canada.
authors.forename: Meghan
authors.initials: M
authors.lastname: Schnittke
authors.affiliation: Division of Clinical Immunology and Allergy, Department of Medicine Michael D. DeGroote School of Medicine, McMaster University, Hamilton, ON Canada.|Grandriver Allergy, Kitchener, ON Canada.|Schulich School of Medicine & Dentistry, Western University, London, ON Canada.
authors.forename: Harold
authors.initials: H
authors.lastname: Kim
keywords: Allergen cross-reactivity; Canadian; Food allergy; House dust mite; Shrimp; Skin test; Tropomyosin