The study will last up to 48 months. Based on the result of the oral food challenge with baked milk the participants will be assigned to either Group 1 (baked milk-tolerant) or Group 2 (baked milk-reactive). Participants in the Group 1 may be further tested with regular, non-heated milk, depending on their diagnostic test results and clinical history. Participants tolerant to non-heated milk will be discharged from the study. Baked milk-tolerant, non-heated milk-reactive participants in Group 1 will receive diet with baked milk at home while Group 2 will act as the control and avoid milk consumption strictly.