NEW YORK, US - CHILDREN who have a potentially life-threatening allergy to cow's milk can often 'learn' to tolerate milk through a carefully orchestrated, supervised program in which they sample milk in progressively higher doses, research suggests.

After one year, more than one-third of cow's milk allergic children who completed the programme had become completely tolerant to cow's milk and more than half could tolerate limited amounts of milk, the research team reports in the Journal of Allergy and Clinical Immunology.

'Desensitisation, or 'specific oral tolerance induction', can be achieved in a significant percentage of children with very severe allergic reactions,' Dr Egidio Barbi from 'Burlo Garofolo' University of Trieste said.Current strategies for managing children with severe food allergy - avoiding the food entirely and carrying epinephrine auto-injectors to quickly halt an allergic reaction - are only partially effective and have a negative impact on quality of life for the entire family, Dr Barbi and his colleagues point out.

For these reasons, the researchers investigated the safety and effectiveness of desensitising children with a history of very severe allergic reactions when exposed to even minor amounts of cow's milk.

Their strategy consisted of two phases. During phase one, the children spent 10 days in the hospital where they were given drops of diluted milk in increasing doses and concentration each day. During phase two, the children followed a similar protocol at home. Parents received written instructions on how to gradually increase the milk dose and were taught how to spot and treat any allergic reactions.

Parents could also contact a doctor involved in the study at any time.

After one year, 11 of the 30 children who completed the protocol were able to tolerate cow's milk and dairy products without any restrictions.

Moreover, another 16 children who completed the desensitisation programme were able to tolerate limited amounts of cow's milk, resulting in a 'striking improvement in quality of life', the investigators note.

The fact that most of the children could tolerate at least some cow's milk after the protocol 'is important because the danger associated with accidental exposure to small amounts of cow's milk is significantly reduced', Dr Barbi and colleagues write.

Three children who had persistent allergic symptoms were not able to complete the milk desensitisation programme.

'Desensitisation carries a definite risk of reactions, especially in children with a severe history,' Dr Barbi emphasised. 'For this reason, it should be restricted to highly defined medical settings.'

Nearly all children who participated in the programme had at least one allergic reaction, mainly skin or stomach problems, which occurred from a few minutes to 2 hours after ingesting milk and were typically managed effectively by the parents. In most cases parents chose to continue the desensitisation programme 'in spite of frequent symptoms', the investigators note.

Dr Barbi and colleagues say they are encouraged by their results but warn that 'far more research is needed to confirm the safety of this approach'. -- REUTERS