Persistence of cow's milk allergy beyond two years of age

Cow's milk allergy (CMA) epidemiology seems to be changing over time, with an increase in prevalence and persistence. Our aim was to characterise a population of children with CMA beyond two years of age, followed up in a Paediatric Allergy Clinic at the tertiary care level.

Retrospective study of children with persistent CMA diagnosed from January 1997 to June 2006. Medical records were analysed regarding: clinical presentation, follow-up, treatment and acquisition of tolerance. Data analysis was performed using Excel 2007 for Windows.

Seventy-nine children were included, with mean age at first symptoms of 3 months. The symptoms were immediate in 93%, with cutaneous (87.3%), gastrointestinal (55.7%) and respiratory (25.3%) manifestations. During the follow-up period, 30% developed atopic eczema, 52% asthma and 35% rhinoconjunctivitis. A family history of atopy was identified in 53%. The majority presented increased serum total IgE (376+/-723 KU/l) and positive skin prick test (SPT) to cow's milk (CM) (79%). SPT to goat's milk was positive in 2/3 of cases. Fifty-five percent had at least one accidental exposure to CM (severe reactions in 6%). During CM elimination diet, 35% were initially given an extensively hydrolysed formula, 17% a soy formula, and 48% both. By the age of 10 years, 44% of children persisted with CMA.

Our population of CM allergic children presented immediate symptoms with cutaneous expression in the majority. Severe reactions were common on accidental exposure. By the age of 10 years, 44% maintained CMA, highlighting the importance of a multidisciplinary follow-up.