Mislabelled Cow's Milk Allergy in Infants
Mislabelled Cow's Milk Allergy in Infants
Background Although cow's milk allergy (CMA) is one of the most common food allergies, mislabelling non-allergic infants as being allergic to cow's milk is more common. Despite this, characteristics of families and infants with mislabelled CMA are lacking.
Methods Using a prospective population-based study, we identified infants with any possible adverse reaction to cow's milk (n=381) from a cohort of 13 019 infants followed from birth. They had a detailed history taken, skin prick tests and an oral food challenge when indicated. Infants with symptoms for which the causative relationship to cow's milk protein was excluded were compared with infants with IgE-mediated CMA and with a control group, and followed for 2–5 years.
Results Overall, 243 infants (1.87%) with mislabelled CMA were identified. Compared with 66 infants with IgE-mediated CMA, those with mislabelled CMA presented earlier and with symptoms usually involving a single organ system. Doctor-diagnosed atopic dermatitis (AD) was associated with mislabelled CMA (p<0.001), manifested primarily as skin rashes, compared with control infants. Higher maternal and paternal education were also associated with mislabelled CMA (p=0.007 and p=0.035, respectively) and manifested primarily as non-specific symptoms.
Conclusions Mislabelled CMA typically presents within the first 3 months of life involving a single organ. Infant AD and higher parental academic education are associated with mislabelled reactions. Better parental and physician awareness of the importance of objectively diagnosing milk allergy is required to avoid mislabelling of infants as being allergic to cow's milk and to prevent potential nutritional deficiencies.
The prevalence of food allergy is low, yet it has been extensively studied. In contrast, mislabelled food allergy is more common but is relatively under-studied. In one study, 30% of women reported that they, or a member of their family, had an allergy to a food product, and 22% of the women avoided particular foods because it may contain an allergen. In another study, 28% of children had symptoms suspected by their parents or primary care physicians of being related to certain foods, but only 8% had confirmed and probable reactions reproduced.
Cow's milk allergy (CMA) is categorised as IgE-mediated or non-IgE-mediated. IgE-CMA typically presents with urticaria, vomiting, cough and wheeze, and, less commonly, hypotension, and develops within minutes to 1–2 h of ingesting cow's milk. Non-IgE-CMA presents with predominantly abdominal symptoms (repetitive vomiting, with or without diarrhoea, abdominal pain and bloody stools) and develops several hours after ingestion of the offending food. Atopic dermatitis (AD) is occasionally associated with food-specific IgE, and many consider worsening of eczema as an expression of CMA. Diagnosis of IgE-CMA depends on the identification of specific IgE antibodies to the offending food, but in both IgE- and non-IgE-CMA an oral food challenge (OFC) is confirmatory.
Multiple adverse effects are often falsely attributed by parents to the consumption of cow's milk, leading to infants being categorised as having CMA. One in every third child was previously reported to have an adverse reaction to food before 2 years of age, and milk was most commonly incriminated (7.5% at 1 year of age). A similar rate was found in another epidemiological study, but the diagnosis was confirmed in only a third of those.
Mislabelled CMA often leads to the unnecessary adoption of an elimination diet, with significant inconvenience and even potential risks. A few studies on infants with mislabelled CMA have found an association with a higher level of maternal education. However, no study to date has separately described these infants. In this study, infants with mislabelled CMA were identified from 13 019 infants followed prospectively from birth for 2–5 years. Symptoms related to consumption of cow's milk protein (CMP) are described, and characteristics of infants and families are compared with a group of infants with IgE-CMA and a control group with no reactions to CMP.
Abstract and Introduction
Abstract
Background Although cow's milk allergy (CMA) is one of the most common food allergies, mislabelling non-allergic infants as being allergic to cow's milk is more common. Despite this, characteristics of families and infants with mislabelled CMA are lacking.
Methods Using a prospective population-based study, we identified infants with any possible adverse reaction to cow's milk (n=381) from a cohort of 13 019 infants followed from birth. They had a detailed history taken, skin prick tests and an oral food challenge when indicated. Infants with symptoms for which the causative relationship to cow's milk protein was excluded were compared with infants with IgE-mediated CMA and with a control group, and followed for 2–5 years.
Results Overall, 243 infants (1.87%) with mislabelled CMA were identified. Compared with 66 infants with IgE-mediated CMA, those with mislabelled CMA presented earlier and with symptoms usually involving a single organ system. Doctor-diagnosed atopic dermatitis (AD) was associated with mislabelled CMA (p<0.001), manifested primarily as skin rashes, compared with control infants. Higher maternal and paternal education were also associated with mislabelled CMA (p=0.007 and p=0.035, respectively) and manifested primarily as non-specific symptoms.
Conclusions Mislabelled CMA typically presents within the first 3 months of life involving a single organ. Infant AD and higher parental academic education are associated with mislabelled reactions. Better parental and physician awareness of the importance of objectively diagnosing milk allergy is required to avoid mislabelling of infants as being allergic to cow's milk and to prevent potential nutritional deficiencies.
Introduction
The prevalence of food allergy is low, yet it has been extensively studied. In contrast, mislabelled food allergy is more common but is relatively under-studied. In one study, 30% of women reported that they, or a member of their family, had an allergy to a food product, and 22% of the women avoided particular foods because it may contain an allergen. In another study, 28% of children had symptoms suspected by their parents or primary care physicians of being related to certain foods, but only 8% had confirmed and probable reactions reproduced.
Cow's milk allergy (CMA) is categorised as IgE-mediated or non-IgE-mediated. IgE-CMA typically presents with urticaria, vomiting, cough and wheeze, and, less commonly, hypotension, and develops within minutes to 1–2 h of ingesting cow's milk. Non-IgE-CMA presents with predominantly abdominal symptoms (repetitive vomiting, with or without diarrhoea, abdominal pain and bloody stools) and develops several hours after ingestion of the offending food. Atopic dermatitis (AD) is occasionally associated with food-specific IgE, and many consider worsening of eczema as an expression of CMA. Diagnosis of IgE-CMA depends on the identification of specific IgE antibodies to the offending food, but in both IgE- and non-IgE-CMA an oral food challenge (OFC) is confirmatory.
Multiple adverse effects are often falsely attributed by parents to the consumption of cow's milk, leading to infants being categorised as having CMA. One in every third child was previously reported to have an adverse reaction to food before 2 years of age, and milk was most commonly incriminated (7.5% at 1 year of age). A similar rate was found in another epidemiological study, but the diagnosis was confirmed in only a third of those.
Mislabelled CMA often leads to the unnecessary adoption of an elimination diet, with significant inconvenience and even potential risks. A few studies on infants with mislabelled CMA have found an association with a higher level of maternal education. However, no study to date has separately described these infants. In this study, infants with mislabelled CMA were identified from 13 019 infants followed prospectively from birth for 2–5 years. Symptoms related to consumption of cow's milk protein (CMP) are described, and characteristics of infants and families are compared with a group of infants with IgE-CMA and a control group with no reactions to CMP.
