Explained: Mumbai hospitals witness ‘alarming’ increase in viral myositis cases

Over 20-25 cases reported in two weeks and a fraction of them needed hospitalisation

people waiting in hospital Representational image | Sanjay Ahlawat

Since the past few weeks, viral myositis is being most commonly observed in clinics and outpatient departments across state-run hospitals in Mumbai. Myositis is inflammation, especially of the voluntary muscles, characterized by pain, tenderness on movement, swelling, acute weakness and high fever. In the past two weeks, doctors have reportedly seen over 20-25 cases and a fraction of them needed hospitalisation. 

"There has been a definite increase in such cases of myositis. This also happened during Covid - once viral fever hits a person and recovers, there may be symptoms such as muscle weakness and muscle inflammation, and these are typically associated with myositis. Mild amount of muscle weakness is associated with viral fever but acute stage is related to myositis," said Dr Sandeep Yadav, consultant rheumatologist, PD Hinduja Hospital in Mumbai. 

What happens in the body when myositis hits?

During viral fever, the body mounts an inflammatory response against the virus and in most cases, within a week or so, the fever vanishes. However, in some cases, this inflammation which was mounted against the viral fever goes haywire and interferes with the body's natural immune system leading to inflammation of all proximal muscles of the body, specifically muscles of the thighs, shoulders, arms and back. So this essentially is post-viral myositis, that is myositis that happens after the viral fever has come and gone. "Some people are genetically susceptible to having inflammation in the muscles as a result of post-viral myositis. In most cases, this settles with paracetamol. Only in acute cases hospitalisation will be needed," says Dr Yadav. 

Dr Paritosh Baghel, senior consultant for internal medicine at SL Raheja Hospital in Mumbai's Mahim says he has also come across "an alarming number” of viral pericarditis and myocarditis cases off late."This is inflammation of the cardiac muscles after a bout of viral fever. People come to me with fever, palpitation and dizziness and discomfort in the chest; it is the ECG that picks up the high heart rate and leads us to suspect them to be cases of myocarditis. We give them symptomatic treatment and that generally resolves the issue. Sometimes when the pain is acute, we need to admit them because severe myositis can also lead to renal failure," says Dr Baghel.