A prospective study of cow milk allergy in Danish infants during the first 3 years of life: Clinical course in relation to clinical and immunological type of hypersensitivity reaction

Abstract

A cohort of 1749 newborns from the municipality of Odense born during 1985 at the University Hospital were followed prospectively for the development of IgE‐mediated and non‐igE‐mediated cow milk allergy (CMA) during their first year. The diagnosis of CMA was based on the results of strict elimination/milk challenge procedures in a hospital setting, and continued clinical sensitivity to cow milk (CM) was assessed by rechallenging every 6–12 months until the age of3 years. Further, in infants with CMA, the Clinical course of adverse reactions to other foods and the development of allergy to inhalant allergens In 3 years were investigated. Of 117 (6.7 %) with symptoms suggestive of CMA, the diagnosis of CMA was proven m 39 infants (2.2%), 64% showed cutaneous symptoms. 59% gastrointestinal symptoms, and 33% had respiratory symptoms. 92% had two or more symptoms and 72 % symptoms from 2 organ systems. Based on a positive skin prick test ( 2 +) and/or AL‐RAST class 2 to CM 16 infants at the time of diagnosis, and at reinvestigation at 1 year, a further five infants giving a total of 21, were classified as having IgE‐mediated CMA, 19 infants showed “immediate reactions to CM (within 1 h after intake of 2.3 g milk protein) and 20 infants were “late reactors”, No significant correlation between IgE‐mediated CMA and “immediate reactions” to CM was demonstrated, The overall prognosis of CMA was good with a total recovery of 22/39 (56%) at 1 year. 30/39 (77%) at 2 years, and 34/39 (87%) at 3 years. Adverse reactions to other foods, particularly egg, citrus, tomato, developed in a total of 21/39 (54%) with the maximum point prevalence of 15/39 (38%) at 18 months, and 9/39 (23%) were still intolerant to other foods at 36 months. Inhalant allergy before 3 years developed in 11/39 (28%), particularly against dog and cat to which the infants had been exposed. Infants with CMA and early IgE, sensitization to CM had an increased risk of persisting CMA (24%) development of persistent adverse reactions to other foods (38%), particularly egg white (29%), and finally, inhalant allergy (48%) before 3 years of age.