The risk was highest among children who received more than four courses of antibiotics, and who were given 'broad-spectrum' drugs for general healthcare.
Researchers in Canada made the discovery when they reviewed the medical histories of 13,116 children. Those who were prescribed antibiotics for anything other than respiratory problems - so eliminating children with a pre-existing condition that might have resulted in asthma - were twice as likely to develop the problem compared with children who weren't given an antibiotic.
The risk could be reduced if children under the age of 12 months weren't prescribed a broad-spectrum antibiotic - or perhaps not give one at all.
(Source: Chest, 2007; 131: 1753-9).