Should milk-specific IgE antibodies be measured in adults in primary care?

OBJECTIVE

To study the association of milk-IgE antibodies in serum to milk-related gastrointestinal symptoms in adults in primary care.

DESIGN

Open clinical study.

SETTING

Five outpatient clinics in primary care in Southern Finland.

SUBJECTS

A total of 756 subjects who reported milk-related gastrointestinal symptoms in primary care and as controls 101 subjects with no such symptoms.

METHODS

IgE values for specific food antigens were measured (Pharmacia CAP System) in a total of 857 subjects. All food screen-positive samples (>0.35 IU/l) were analysed further for IgE for untreated skimmed milk (milk-IgE) and for boiled milk. Those found positive for milk-IgE were invited for an open milk challenge test.

RESULTS

Some 5.4% (46/857) of all subjects had a positive IgE antibody screen for food antigens. Of those with a positive food screen, 28% (13/46) had milk-IgE antibodies comprising 1.5% of the total group screened. The prevalence of milk-IgE was not statistically different between those with milk-related symptoms and those with no such symptoms. IgE antibodies for boiled milk were rare. All specific IgE antibody levels were low. Bloating was the only observed symptom in milk challenge tests.

CONCLUSION

IgE antibodies to cow's milk were relatively rare in the adult population and were not indicative of milk protein allergy. The observed IgE levels were low and did not correlate with subjective milk-related symptoms. The measurement of milk-specific IgE in adults should be discouraged in outpatient clinics.