Tolerance to egg proteins in egg-sensitized infants without previous consumption.

BACKGROUND: Egg-sensitized infants who have never eaten egg may react at first ingestion. We sought to determine the association between skin prick test (SPT) and specific IgE (sIgE) to egg proteins (EP) and oral food challenge (OFC) outcomes to find cut-off points which can diagnose egg allergy. METHODS: One hundred and fifty-four infants up to 18 months, with cow's milk allergy (CMA) and/or atopic dermatitis (AD) without previous egg consumption, were recruited. SPT to EP were performed. If it was positive, sIgE was performed. If positive SPT and/or sIgE (n = 94), OFC was performed between 12 and 18 months. Receiver operating characteristic (ROC) curves were plotted, and the outcome of the OFC was related to SPT and sIgE. The cut-off points with the best diagnostic accuracy were found. RESULTS: Ninety-four patients were sensitized to egg (69%) and 60 nonsensitized (31%). Of the sensitized, 27 tolerated cooked (CE) and raw egg (RE) (28.7%). Sixty-seven were allergic (71.3%): 29 reacted to CE, seven to egg yolk (EY) and 22 to egg white (EW) and 38 reacted to RE. 69.2% tolerated CE. EW SPT and ovalbumin (OVA) sIgE have the best area under the curve (AUC). The higher positive predictive values (PPV) were obtained for EW SPT and EW sIgE. CONCLUSIONS: In egg-sensitized infants with EW SPT ≥8 mm and/or EW sIgE ≥8.36 KU/l, egg diagnostic OFC can be avoided as there is 94% probability of becoming positive. In the other patients, OFC should be performed safely and early to avoid unnecessary diets.

Safety and predictors of adverse events during oral immunotherapy for milk allergy: severity of reaction at oral challenge, specific IgE and prick test.

BACKGROUND: Strict avoidance is the only accepted management for cow's milk (CM) allergy. CM oral immunotherapy (CM-OIT) is under investigation. OBJECTIVES: To evaluate long-term safety of CM-OIT. To identify clinical/immunological predictors of adverse events. METHODS: Prospective longitudinal epidemiological intervention study. CM-allergic children aged 5-18 underwent a Spanish-approved CM-OIT protocol without premedication. Clinical data, skin prick test (SPT) and specific IgE (sIgE) at baseline and 1 year after OIT were registered. All dose-related reactions, treatments needed and cofactors involved were recorded. Through survival analysis, we studied the cumulative probability of reactions resolution over time and clinical/immunological risk factors of reactions persistence. RESULTS: 81 children were recruited. Mean follow-up was 25 months. 95% of children suffered reactions, 91% of which affected a single organ. Reactions were heterogeneously distributed: (a) 60 children (75%) had occasional symptoms which ceased over time. 86% of them reached complete desensitization (200 mL). (b) 20 children (25%) suffered frequent (78% of total reactions), more severe and unpredictable reactions, which persisted during follow-up or led to withdrawal (6 cases). Reactions persistence was associated with a higher frequency and severity. Kaplan-Meier estimate revealed a cumulative probability of reactions resolution of 25% at 3 months (95% CI: 1.9-4.1) and 50% (95% CI: 6.1-9.9) at 8 months based on all patients. Cox proportional hazards multivariate regression model identified 3 variables (CM-sIgE ≥ 50 KU L(-1) , CM-SPT ≥ 9 mm and Sampson's severity grades 2, 3 and 4 at baseline food challenge) as independent risk factors of reactions persistence. The combination of 2 or 3 of these factors involved hazard ratios to develop persistent reactions of 2.26 (95% CI: 1.14-4.46; P = 0.019) and 6.06 (95% CI: 2.7-13.7; P < 0.001), respectively. CLINICAL IMPLICATIONS: CM-OIT was insufficiently safe in 25% of children. The above-mentioned clinical and immunological parameters would help clinicians to identify highly reactive patients before CM-OIT. In them, individualized schedules and premedication should be considered.