Onset of Nut Allergy in a Pediatric Cohort: Clinical and Molecular Patterns in the AFRUSEN Study.

BACKGROUND AND OBJECTIVE: Nut allergy is a growing problem, yet little is known about its onset in children. Objective: To characterize the onset of nut allergy in children in southern Europe. METHODS: The study population comprised consecutive patients up to 14 years of age who visited allergy departments with an initial allergic reaction to peanut, tree nut, or seed. The allergy work-up included a clinical history, food challenge, skin prick testing, determination of whole-extract sIgE, and ImmunoCAP ISAC-112 assay. RESULTS: Of the 271 children included, 260 were first diagnosed with nut allergy at a mean age of 6.5 years and at a mean (SD) of 11.8 (21.2) months after the index reaction. The most common culprit nuts at onset were walnut (36.5%), peanut (28.5%), cashew (10.4%), hazelnut (8.5%), pistachio (5.4%), and almond (5%). Onset of peanut allergy was more frequent in children ≤6 years and walnut in those aged >6 years (P=.032). In 65% of cases, the allergic reaction occurred the first time the patient consumed the nut, and 35% of reactions were anaphylactic. Overall, polysensitization to nuts was detected by skin prick testing in 64.9% of patients, although this rate was lower among walnut-allergic children (54.7%) and peanut-allergic children (54.1%) (P<.0001). Sensitization to 2S albumins was predominant (75%), especially Jug r 1 (52.8%), whereas sensitization to lipid transfer proteins was less relevant (37%). CONCLUSION: In the population we assessed, the onset of nut allergy occurred around 6 years of age, slightly later than that reported in English-speaking countries. Walnut was the main trigger, followed by peanut. 2S albumin storage proteins, especially Jug r 1, were the most relevant allergens. This study will help guide management and may contribute to preventive strategies in pediatric nut allergy.

Syndrome auriculotemporal.

Two cases of auriculotemporal syndrome are presented in two male children that began in the first years of life to present reactions of linear erythema itinerary on the cheeks after eating several foods. The allergologic study with these foods was negative, reproducing the clinical picture after their ingestion.

Specific IgE levels in the diagnosis of immediate hypersensitivity to cows' milk protein in the infant.

BACKGROUND: A milk-free diet with substitute formula should be established when immediate symptomatic hypersensitivity to cows' milk protein (CMP) is diagnosed, and therefore an accurate diagnosis is very important. OBJECTIVE: This study aims to find the optimal cutoff values for specific IgE antibody levels that discriminate between allergic and tolerant infants by using cows' milk and its principal proteins as allergens. METHODS: A prospective study was carried out on 170 patients under 1 year old (mean, 4.8 months). These patients were seen consecutively over a 4-year period in our outpatient clinic and for the first time because of a reaction suggesting immediate hypersensitivity after ingestion of cows' milk formula. A clinical history, prick test with cows' milk and its proteins (alpha-lact-albumin, beta-lactoglobulin, and casein), determination of specific IgE antibodies with the CAP system FEIA for the same allergens as for the prick test, and a challenge test according to the diagnostic protocol were performed in all of the children. A study of validity of the prick test (cutoff point, 3 mm) and CAP system by using different cutoff points in the specific IgE values for cows' milk and its proteins were also analyzed. RESULTS: Prevalence of immediate symptomatic hypersensitivity to CMP in this study was 44%. When both the whole milk and its principal milk proteins were used in the prick test, the negative predictive value was very high, and a negative value excluded allergy in 97% of the patients. When the different cutoff points of the specific IgE for milk were analyzed, 2.5 KU(A)/L had a positive predictive value of 90% and 5 KU(A)/L had a positive predictive value of 95%. CONCLUSIONS: When diagnosing immediate hypersensitivity to CMP in infants, negative skin test responses exclude allergy in most of the patients. If the prick test response is positive, specific IgE levels for cows' milk may be helpful. If these values are 2.5 KU(A)/L or greater, the challenge test should not be performed because of its high positive predictive value (90%).