Background: Cow's milk protein allergy (CMPA) is the most common food allergy during the first year of life. Strict avoidance of specific foods is the only accepted treatment for food-induced allergic reactions. This is often an unrealistic therapeutic option, since cow's milk is a basic food that is extensively used in infant formula. The recent preliminary experience of oral desensitization to cow's milk by Meglio & Patriarca seems promising. The object of this study was to investigate the desensitization of children with CMPA to cow's milk.

Methods: All the patients referred to the Allergology Department of the Children's Medical Center Hospital, Tehran from March 2004 to November 2005 suspected to have CMPA were evaluated. The patients were included in the intervention or control groups of the study. For the intervention group, Meglio's protocol was performed. We observed and examined the control group for at least 6 months. Eventually both groups were reevaluated for the symptoms and persistence of positive specific IgE for cow milk proteins.

Results: We enrolled 20 patients for oral desensitization and 13 patients were enrolled in the control group. Both groups were similar with regard to the mean age, sex and clinical symptoms. In 18 (90%) of the intervention subjects, oral desensitization with cow's milk was successfully performed. The entire protocol was completed by 14 (70%) of the intervention subjects. At the end of the six-month observation period, all the patients in the control group were still symptomatic after ingestion of cow's milk. The levels of specific IgE for cow's milk in the intervention group decreased significantly, which was not observed in the control group.

Conclusion: We successfully desensitized 90% of our CMPA patients. Considering that all the patients in the control group remained symptomatic after the period of observation and our promising results in oral desensitization with cow's milk, we can safely propose this protocol as a hopeful alternative in the treatment of CMPA. We speculate that oral desensitization to cow's milk does not alter the natural outcome of CMPA, but substantially increases the threshold dose necessary to elicit allergic symptoms.