IgE-mediated Cow's Milk Allergy in Brazilian Children: Tolerance Development at five years of age

Abstract

RATIONALE: Cow's milk allergy (CMA) is an important food allergy in infants and the majority of patients present remission within 3 years of age. Recently many authors have described a delayed tolerance to cow's milk (CM) in children. The objective of this study is to describe the natural history of CMA until five years of age in Brazilian children followed at a tertiary allergy reference center.METHODS: It was followed 89 CMA patients evaluated at 5 years regarding tolerance development. The criteria adopted for CMA IgE-mediated were: clinical immediate reaction triggered by CM, presence of specific IgE to CM and/or its fractions and anaphylaxis or DCPC positive test. The tolerance criterion was defined as absence of symptoms to: DCPC test, open challenge or accidental exposure to CM.RESULTS: The clinical manifestations included cutaneous, gastrointestinal, respiratory symptoms and anaphylaxis observed in 56.2% of patients. The age of the first patient who developed tolerance was 18 months. The rates of tolerance in terms of age were: 6.7% at 2 years, 27.0% at 3 years, 37.1% at 4 years and only 44.9% at 5 years.CONCLUSIONS: The development of tolerance to CM in these Brazilian patients was delayed in comparison to many reports about it. This result may be a consequence of the higher anaphylaxis rate found in this population evaluated in a tertiary allergy reference center. RATIONALE: Cow's milk allergy (CMA) is an important food allergy in infants and the majority of patients present remission within 3 years of age. Recently many authors have described a delayed tolerance to cow's milk (CM) in children. The objective of this study is to describe the natural history of CMA until five years of age in Brazilian children followed at a tertiary allergy reference center. METHODS: It was followed 89 CMA patients evaluated at 5 years regarding tolerance development. The criteria adopted for CMA IgE-mediated were: clinical immediate reaction triggered by CM, presence of specific IgE to CM and/or its fractions and anaphylaxis or DCPC positive test. The tolerance criterion was defined as absence of symptoms to: DCPC test, open challenge or accidental exposure to CM. RESULTS: The clinical manifestations included cutaneous, gastrointestinal, respiratory symptoms and anaphylaxis observed in 56.2% of patients. The age of the first patient who developed tolerance was 18 months. The rates of tolerance in terms of age were: 6.7% at 2 years, 27.0% at 3 years, 37.1% at 4 years and only 44.9% at 5 years. CONCLUSIONS: The development of tolerance to CM in these Brazilian patients was delayed in comparison to many reports about it. This result may be a consequence of the higher anaphylaxis rate found in this population evaluated in a tertiary allergy reference center.