Patients with severe asthma who are allergic to certain fungi may benefit from an anti-fungal drug, says a new study.

Researchers from the University of Manchester in England have found that the drug used to treat fungal infections have shown to greatly improve in patients with severe asthma with fungal sensitization, or "SAFS".

"We knew that many people with severe asthma are sensitized to several airborne fungi which can worsen asthma without overt clinical signs. The question was: does antifungal therapy provide any clinical benefit," said David Denning, F.R.C.P., F.R.C.Path., professor of medicine and medical mycology at The University of Manchester and lead investigator of the study.

During the study, the researchers recruited 58 patients with severe asthma and allergic sensitivity to at least one of seven different common fungi.

They were randomly assigned to receive either an oral dose of itraconazole (200mg twice a day) or a placebo.

The results showed that 62 percent of the patients who were randomised to receive the drug experienced significant improvements on their Asthma Quality of Life Questionnaires, and in runny nose and morning lung function.

However, 11 of the patients who received the drug left the trial before completion, some citing side effects that included nausea, breathlessness and muscle weakness. Unfortunately, four months after stopping antifungal treatment, symptoms had returned.

"This study indicates that fungal allergy is important in some patients with severe asthma, and that oral antifungal therapy is worth trying in difficult-to-treat patients. Clearly itraconazole will not suit everyone and is not always helpful, but when it is the effect is dramatic," said Denning.