Objectives: The aims of this study were to determine the incidence of allergy to cow's milk protein in infants and the cost of treatment with hydrolyzed formulae in the Autonomous Community of Madrid.
Patients and methods: Infants with suspected adverse reaction to cow's milk protein born between March 1, 2000 and February 28, 2001 within the catchment area covered by the pediatric services of Hospital La Paz were studied. The diagnostic algorithm of allergy to cow's milk protein of our department was used. The theoretical consumption of hydrolyzed formulae in the treatment of allergic infants was calculated and extrapolated to the Community of Madrid.
Results: There were 5367 live births in the above-mentioned catchment area. Adverse reaction to cow's milk protein was suspected in 185 infants. Allergy to cow's milk protein was confirmed in 101 (54 %). The incidence of allergy to cow's milk protein was 101/5356 (1.9 %). In the same period there were 57 078 live births in the Autonomous Community of Madrid. The number of infants that might be allergic in one year would be 1084. The cost of hydrolyzed formulae per infant and year would be 1,585.72 Euros. Thus, the cost of hydrolyzed formulae in the 1084 allergic infants would be 1,718,922.9 Euros; in the 923 in whom allergy was ruled out, the cost would be 1,463,621.8 Euros.
Conclusions: The incidence of allergy to cow's milk protein in the first year of life is at least 1.9 %. The correct diagnosis allows us to rule out allergy to cow's milk protein in almost half of the cases, thus avoiding the use of unnecessary substitutive diets involving a high cost.