NEW YORK (Reuters Health) – Cow’s milk oral immunotherapy appears to desensitize milk allergic children, a study indicates, although further work is needed to determine optimal dosing and duration of therapy as well as whether permanent tolerance can be achieved, the study team emphasizes.

In the study, 20 children, 6 to 17 years of age, with a known history of IgE-mediated milk allergy were randomized to placebo or to milk in a 3-phase dosing schedule. On the first build-up day, a dose of 0.4 mg milk protein was administered in the clinical research facility, with dose escalation about every 30 minutes to a maximum first-day dose of 50 mg.

Home daily dosing was then initiated at the highest dose tolerated on the build-up day, with 8 weekly in-office dose increases to a maximum of 500 mg. Once a dose of 500 mg (equivalent to 15 mL of milk) was achieved, participants remained on this daily maintenance dose for 13 weeks.

According to a report in the Journal of Allergy and Clinical Immunology for December, 12 children in the active group and 7 in the placebo group completed the study.

One child dropped out due to persistent eczema during dose escalation. According to Dr. Robert A. Wood from The Johns Hopkins Hospital, Baltimore and colleagues: “Adverse reactions were common, but the risk of a severe reaction fell within the range that we would consider acceptable. Despite the relatively high frequency of reactions of any type (45% of active doses), nearly 90% were transient reactions that required no treatment.”

They also report that milk oral immunotherapy was effective in increasing the threshold for reactions to milk in all treated children.

Before treatment, nearly all children had symptoms after a median challenge dose of 40 mg of milk. Following milk oral immunotherapy, the average cumulative milk dose causing a reaction was 5140 mg, with no change in the placebo group. After milk immunotherapy, the lowest milk dose to cause a reaction was 1340 mg, “which is still likely to be protective against the overwhelming majority of accidental exposures,” the investigators note.

However, despite an increased threshold after completion of milk oral immunotherapy, post-treatment food challenge still elicited reactions in 14 of 18 children (including children in the placebo group who later opted for open-label active treatment), Dr. Wood and colleagues point out. Even in those who did not react to the post-treatment food challenge, “it is not clear whether they are fully tolerant or rather transiently desensitized and thus still at risk of future reactions,” the researchers note.

Reference:
J Allergy Clin Immunol 2008;122:1154-1160.