Giving antihistamines or decongestants to children with persistent fluid in the middle ear is more likely to harm them than to help, a new review suggests.

The condition, called otitis media with effusion or OME, is one of the most common in young children. About nine of 10 children will have it at least once before school age, the researchers said. The short-term inflammation of the middle ear can be caused by viral or bacterial infection.

It is usually not painful, but the fluid can cause problems with hearing and balance.

Antihistamines and decongestants commonly used to treat allergy and cold symptoms may be prescribed for the ear condition, but a review of studies concluded the drugs are no better than a placebo for alleviating symptoms or avoiding complications.

"There is absolutely no question that these products don't work," said Dr. Richard Rosenfeld, a pediatric otolaryngologist in Brooklyn, N.Y. Rosenfeld chaired the 2004 American Academy of Pediatrics guidelines for OME, which recommends against the use of antihistamines and decongestants because the harm outweighs the benefits.

Deceptive mental image

"Parents will say, 'My doctor gave me these medications to dry up the fluid,' or, 'If I use this, it's going to open the eustachian tube.' Apparently that mental image is so powerful that it completely overwhelms common sense regarding the management of this disorder."

Dr. Glenn Griffin of Quinte West Medical Centre in Ontario led the study, which appears in the current issue of The Cochrane Library, which publishes reviews of medical trials.

"This review finds no benefit for any of the short- or long-term outcomes, including resolution of the fluid, hearing problems or the necessity of additional referral to specialists," Griffin said. "However, treated study subjects experienced 11 per cent more side-effects than untreated subjects."

Griffin's team pooled the results of 15 randomized controlled trials involving 1,516 children, comparing antihistamines, decongestants or the combination to a placebo for the ear condition.

The findings were consistently negative. Children who received the allergy medications were no more likely to be cured within one month than children who took a placebo, and the results were the same after more than three months.

There was a small statistical benefit from combining the medications, but it did not mean much clinically and the study design may have biased the results, the researchers said.

In six studies that looked at side-effects, 17 per cent in the medication group showed side-effects, compared with six per cent in the placebo group.

Side-effects of antihistamines and decongestants include insomnia, hyperactivity, drowsiness, behavioural changes and changes in blood pressure.