%0 Journal Article
%T Prevalence and risk factors for milk allergy overdiagnosis in the BEEP trial cohort.
%A Allen HI
%A Wing O
%A Milkova D
%A Jackson E
%A Li K
%A Bradshaw LE
%A Wyatt L
%A Haines R
%A Santer M
%A Murphy AW
%A Brown SJ
%A Kelleher M
%A Perkin MR
%A Jay N
%A Smith TDH
%A Moriarty F
%A Montgomery AA
%A Williams HC
%A Boyle RJ
%J Allergy
%V 0
%N 0
%D 2024 Jun 20
%M 38899450
%F 14.71
%R 10.1111/all.16203
%X <B>BACKGROUND: </B>Cow's milk allergy (CMA) overdiagnosis in young children appears to be increasing and has not been well characterised. We used a clinical trial population to characterise CMA overdiagnosis and identify individual-level and primary care practice-level risk factors.<BR><B>METHODS: </B>We analysed data from 1394 children born in England in 2014-2016 (BEEP trial, ISRCTN21528841). Participants underwent formal CMA diagnosis at ≤2 years. CMA overdiagnosis was defined in three separate ways: parent-reported milk reaction; primary care record of milk hypersensitivity symptoms; and primary care record of low-allergy formula prescription.<BR><B>RESULTS: </B>CMA was formally diagnosed in 19 (1.4%) participants. CMA overdiagnosis was common: 16.1% had parent-reported cow's milk hypersensitivity, 11.3% primary care recorded milk hypersensitivity and 8.7% had low-allergy formula prescription. Symptoms attributed to cow's milk hypersensitivity in participants without CMA were commonly gastrointestinal and reported from a median age of 49 days. Low-allergy formula prescriptions in participants without CMA lasted a median of 10 months (interquartile range 1, 16); the estimated volume consumed was a median of 272 litres (26, 448). Risk factors for CMA overdiagnosis were high practice-based low-allergy formula prescribing in the previous year and maternal report of antibiotic prescription during pregnancy. Exclusive formula feeding from birth was associated with increased low-allergy formula prescription. There was no evidence that practice prescribing of paediatric adrenaline auto-injectors or anti-reflux medications, or maternal features such as anxiety, age, parity and socioeconomic status were associated with CMA overdiagnosis.<BR><B>CONCLUSIONS: </B>CMA overdiagnosis is common in early infancy. Risk factors include high primary care practice-based low-allergy formula prescribing and maternal report of antibiotic prescription during pregnancy.