A Retrospective Study of Clinical Shrimp Allergy in the Setting of Shrimp, Cockroach and Dustmite Sensitization

Rationale:   The protein that commonly causes shrimp allergy, tropomyosin, is also found in cockroach and dust mite (DM). The presence of clinical shrimp allergy and immunologic sensitization amongst these allergens is underreported and therefore merits further investigation.

Methods:   A retrospective chart review was conducted on patients ages 5 through 80 with allergy clinic visits from Jan 2012 through Jun 2015. Data was collected on shrimp, cockroach, and dustmite sensitization based on IgE skin prick (Dermapik®) or in-vitro (immunoCAP®) testing. A history of clinical reactivity to shrimp was recorded to determine the prevalence of shrimp allergic symptoms in the presence of shrimp, cockroach or DM sensitization.

Results: Of 171 patients analyzed, 46 (27%) was sensitized to shrimp, 77 (45%) to cockroach, 89 (52%) to DM, 31 (18%) to SH+/CR+/DM+, and 2 (1.2%) to SH+/CR-/DM-. Clinical shrimp allergy was reported by 57% (26/46), 34% (26/77), and 34% (30/47), respectively, with sensitization as compared to 17% (21/124, p=<0.0001), 22% (21/94, p=0.10), and 21% (17/82, p=0.06) without sensitization to shrimp (OR=6.4, 95% CI 3.0-13.6, p<0.0001), cockroach (OR=0.6, 95% CI 0.2-1.5, p=0.29), and DM (OR=1.1, 95% CI 0.5-2.5, p=0.76), respectively. Shrimp allergy was reported in 51% vs. 86% (p=0.12) with SH+/CR+ vs. SH+/CR- and 56% vs. 60% (p=1.0) with SH+/DM+ vs. SH+/DM-.

Conclusions: Shrimp sensitization was the only predictor that is significantly associated with clinical shrimp allergy. Cockroach or DM sensitization was not found to significantly increase the odds of having a history of clinical shrimp allergy.