Background There is limited knowledge regarding long term follow-up of milk allergic patients who tolerate baked milk (BM) products.

Aim To evaluate the long-term safety and efficacy of this intervention.

patients and methods Children with IgE-mediated milk allergy underwent an oral challenge with BM. Those who tolerated BM underwent baked cheese pizza (BC) challenge after 6 months. Six months later, a challenge with unheated milk was offered to patients who tolerated BC.

Results 85 children (median 5.2 years; range 15 months to 15 years) were prospectively followed for a median of 29 months (range 15–50 months). Fifteen (18%) reacted to the initial BM challenge. Reactions were mild in most cases an only 3 had anaphylaxis. Among 70 (82%) children who initially tolerated BM challenge, 26 (37%) tolerated unheated milk at last follow up, 16 (23%) tolerated BM/BC and 25 (36%) avoided all forms of milk despite successful initial BM/BC challenges. Another 3 patients (4%) were lost to follow-up. Predictive parameters of reactivity to initial BM challenge include age (median – 7; range 2.5–15 years vs. 3.5; range 1–14.5 years; p=0.02), mild respiratory symptoms (67% vs. 26%, p<0.01) as part of the reported allergic reaction to milk, asthma (53% vs. 14.3%, p<0.01) and a larger SPT to casein (median 14; range 8–28 mm vs. 6; range 0–18 mm; p<0.01)

Conclusions For most of our patients, ingestion of BM was found to be safe and well tolerated. However, initial successful challenge with BM/BC does not always guarantee ongoing consumption of these products. Better predictors of response are needed for patient selection and long term outcomes.