[Relationship between the sensitization to shrimp and mites. Exploration of cross-reactivity due tropomyosin]

Little is known out the sensitization to shrimp in patients with respiratory allergies who are sensitized to mites and about the clinical relevance of that sensitization in the tropical region.

To determine the prevalence of sensitization to shrimp in patients with rhinitis or asthma who are sensitized to mites, to explore the route of sensitization, its relevance, and the role of sensitization to tropomyosin.

A cross-sectional study in patients with asthma and rhinitis who are sensitized to mites. Through a survey, it was asked about the consumption of shrimp and the control of asthma or rhinitis. Oral provocation tests were carried out with shrimp on individuals who are sensitized to mites and shrimp without consumption, or consumption greater than six months before, without reaction history. In a subgroup, the sIgE was measured for shrimp, Der p and Lit v 1. The patients who are sensitized to mites and shrimp (cases) were compared to the patients who are sensitized only to mites (controls).

Out of 229 patients, 48 (21%) were sensitized to shrimp. There wasn't a statistically significant difference in the intake of shrimp between cases (54.2%) and controls (49.7%); eight cases showed symptoms on contact with shrimp. No statistically significant differences were found in the sIgE for Der p, Lit v1 and shrimp between cases and controls. A medium change was observed in the size of the effect: 0.45, 0.44 and 0.41 respectively.

Sensitization to shrimp in patients with asthma or allergic rhinitis caused by mites is high; in 25% it seems to be clinically relevant, mainly in those with asthma. Intake is not the main route of exposure to tropomyosin; cross-reactivity can explain the frequency of sensitization.