Previous trials have found this probiotic strain, produced by the Finnish dairy Valio, to lower the chances of children developing eczema.
A team from the University of Turku in Finland reported in 2003 that children who were exposed to the LGG bacteria around the time of birth were 40 per cent less likely to develop atopic eczema at four years of age compared with children in a placebo group.
In the new study, Dr Mirva Viljanen and colleagues from the University of Helsinki assessed symptoms in 230 infants who already had eczema, thought to be an allergy to cow's milk. Around 2-3 per cent of infants are allergic to milk proteins.
The children were given either LGG alone, LGG combined with three other probiotic bacteria, or a placebo for four weeks. They also followed a specific diet and skin treatment.
At the end of the treatment, the researchers tested for an allergy to cow's milk and found 120 infants to be allergic.
Allergy symptoms dropped by 65 per cent overall during the study, but no differences were observed between the different groups, write the researchers in this month's issue of Allergy (vol 60, issue 4, pp494-500).
However, when they looked only at subjects sensitized to the antibody IgE, shown to play a major role in allergies, the LGG treatment had a greater effect on symptom severity than placebo, or the probiotic combination.
Exclusion of infants who had received antibiotics during the study reinforced the findings in the IgE-sensitized subgroup, said the authors.
"Treatment with LGG may alleviate atopic eczema/dermatitis syndrome symptoms in IgE-sensitized infants but not in non-IgE-sensitized infants," they report.