Researchers have found that oral steroid use in patients with inflammatory diseases significantly increases the risk of infection and the risk increases with higher doses.

The study, published in the journal CMAJ, picked over 40,000 adult patients with polymyalgia rheumatica or giant cell arteritis in England. The researchers found higher risks of infection when patients were taking oral steroids than when they were not taking them. "In periods with prescribed medication, patients' risk was 50 per cent higher than when it was not prescribed, increases in risk ranged from 48 per for fungal to 70 per cent for bacterial infections," said Mar Pujades-Rodriguez, from the University of Leeds in the UK.

Steroids included prednisolone, prednisone, hydrocortisone and cortisone. The risk of infection increased with higher doses and was elevated even with low daily doses of less than 5 mg of prednisolone. According to the findings, more than half of the patients (22,234 or 56 per cent) had infections, with the most common being lower respiratory tract infections (27 per cent), conjunctivitis (nine per cent) and shingles (seven per cent). More than 27 per cent of patients were admitted to hospital and seven per cent died within a week of diagnosis of infection, said the study. Patients and clinicians should be educated about the risk of infection, need for symptom identification, prompt treatment, timely vaccination and documentation of history of chronic infection, researchers said.