The Natural History of Shrimp Allergy in Thai Patients

Abstract

RATIONALE: Shrimp is the most common cause of food hypersensitivity in adolescences and adults. Study on the natural history of shrimp allergy is scarce. The objective of this study is to examine the natural course of shrimp allergy and the predictor for its resolution. METHODS: Patients who were diagnosed as having shrimp allergy by positive oral food challenge (OFC) to Penaeus monodon (Pm) and Macrobrachium rosenbergii (Mr) were recruited. They were asked to repeat the second OFC after 10 years of follow up. The skin prick tests using extracts of Pm (PmSPT), Mr (MrSPT), and prick-to-prick tests of both shrimp species (PmPTP, MrPTP) were performed. RESULTS: Fourteen patients (aged 21.662.7 years) were evaluated. The previous reaction to Pm, Mr or both shrimp species were found in 7, 7 and 4 patients, respectively. The mean duration between the first and second OFC was 11.161.6 years. The second OFC were negative in 4/7 of Pm and 4/7 of Mr allergy. In patients who have positive OFC, 5/6 patients had less severe reactions. Two of eight patients who strictly avoided and 6/6 patients who did not strictly avoid shrimp in their diet could tolerate shrimp upon second OFC (p50.01). The skin test sizes were decreased in all patients. However, only MWD from MrSPT reduced significantly from 10.0 mm to 4.0 mm (p50.03). CONCLUSIONS: In this selected patients with shrimp allergy, about half of participants can outgrow. Predictive factor for shrimp tolerance was reintroducing shrimp into diets.

IgE Mediated Shellfish Allergy in Children—A Review

“…Contrasting data on rates of tolerance development in children with shellfish allergy have been provided. Natural resolution after 5–10 years has been described in a percentage of patients ranging from 3.9% in a questionnaire study including both adults and children [ 60 ] up to 46% in a study conducted with an oral challenge in children with non-anaphylactic reactions [ 61 ]. It is unclear whether the latter findings are restricted to a subgroup of children.…”