Assessing diagnostic tests for shrimp allergy in children: A multicenter trial.

BACKGROUND

Clinical research on pediatric shrimp allergy is limited.

OBJECTIVE

We sought to evaluate the diagnostic accuracy and safety of testing methods for shrimp allergy.

METHODS

An oral food challenge (OFC) for shrimp was conducted on Japanese children with suspected shrimp allergy. Before the OFC, shrimp-, tropomyosin-, house dust mite-, and cockroach-specific IgE levels were measured, along with skin prick tests (SPTs). OFC results using epinephrine as a safety indicator determined persistent, mild, or tolerant shrimp allergy.

RESULTS

Sixty-six children (median age, 6 years) underwent the OFC. All patients demonstrated house dust mite-specific IgE level exceeding 0.35 IUA/mL. Sixteen were diagnosed with persistent shrimp allergy, defined by Anaphylaxis Scoring Aichi scores greater than or equal to 10 or scores of 5 with urticaria. A 15-year-old required epinephrine for anaphylaxis. Eight children with negative results (scores ≤ 9) reported mild symptoms after repeated home ingestion following the OFC. Median SPT wheal diameters in persistent, mild allergic, and tolerant groups were similarly elevated (8.5 vs 9.5 vs 8.0 mm;  = .99). Patients with persistent shrimp allergy had higher median shrimp- and tropomyosin-specific IgE level than those classified as mild or tolerant (shrimp: 73.5 vs 30.0 vs 9.4 IUA/mL;  = .01; tropomyosin: 68.0 vs 41.9 vs 11.5 IUA/mL;  = .16). Receiver-operating characteristic analysis determined optimal IgE cutoff values as 58.2 IUA/mL for shrimp-specific IgE and 33.5 IUA/mL for tropomyosin-specific IgE.

CONCLUSIONS

SPT showed limited symptom correlation, whereas shrimp-specific IgE demonstrated greater diagnostic value than tropomyosin-specific IgE. No IgE cutoff accurately predicts a successfully passed OFC.