Use of CT scans and steroids for COVID-19

Why have doctors cautioned against exposing people, especially those with mild symptoms, to radiation?

As doctors try out different protocols to manage patients with COVID-19, Dr. Randeep Guleria, director of the All India Institute of Medical Sciences (AIIMS) and member of the National Taskforce on COVID-19, has cautioned against the use of CT scans indiscriminately to diagnose the disease, especially in the early stages. This exposes individuals to unnecessary radiation, which could be harmful in the long run, he said. A single CT scan is equal to 300 X-rays, Dr. Guleria warned, which may increase the risk of cancer later in life for young people. Doctors and the World Health Organization (WHO) are also cautioning against the use of corticosteroids like dexamethasone, a potent anti-inflammatory drug, for patients who have non-severe COVID-19. Corticosteroids have been proven to benefit patients with moderate and severe infection. An RT-PCR test is the standard for diagnosis or confirmation of COVID-19. Use of CT for the diagnosis of COVID-19 should be restricted to that subgroup of patients who may have classical symptoms of the illness but have a negative RT-PCR test result. However, a chest CT can be useful in evaluating patients with moderate or severe disease, to identify complications like thromboembolism or pneumomediastinum.