Three-year prognosis after low-dose oral food challenge for children with wheat allergy.

BACKGROUND: Low-dose oral food challenge (LD-OFC) is an approach to avoid complete elimination in high-risk patients with wheat allergy (WA). We examined the 3-year prognosis after LD-OFC among patients who passed and failed LD-OFC.

METHODS: Children with immediate-type WA aged ≤6 years with a history of reaction to ≤390 mg of wheat protein underwent their first LD-OFC with 52 mg (baseline LD-OFC). After passing the LD-OFC, children stepped up to 390, 1300, and 5200 mg step-by-step every 3-6 months. After failing LD-OFC, children repeated LD-OFC every 6-12 months. We assessed wheat tolerance defined as consuming 5200 mg without symptoms for 3 years after baseline LD-OFC.

RESULTS: The median age of 124 children was 2.4 years, and the wheat- and ω-5-gliadin-specific immunoglobulin E (IgE) levels (kUA /L) were 23.6 and 2.1, respectively. Upon baseline LD-OFC, 57% passed (LD-tolerant), whereas 43% failed (LD-reactive). Within 3 years, 38% of the LD-reactive group passed re-administered LD-OFC, and 70% of all participants avoided complete elimination. The percentage of the participants who became capable of consuming 390 mg (87% vs. 18%), 1300 mg (78% vs. 13%), and acquired tolerance (70% vs. 13%) was significantly higher in the LD-tolerant group than in the LD-reactive group (p < 0.001). Predictors of persistent WA in the LD-tolerant group were older age (adjusted odds ratio, 1.63), ω-5-gliadin-specific IgE level (1.62 per 10-fold increase), and other food allergies (1.94).

CONCLUSIONS: LD-tolerant patients frequently acquired wheat tolerance within 3 years. Even if once positive, one-third could pass the re-administered LD-OFC within 3 years.