Muscle pain in infants

Muscle pain in infants: Possible causes

Muscle pain (myalgia) in infants is a relatively rare complaint that is difficult to diagnose. Unlike older children, who often experience "growing pains", in infants muscle pain is usually associated with an acute condition.

Most common causes of muscle pain

• Post‑viral myositis: Acute pain and weakness in the muscles (most often in the calves) that occurs 1-2 weeks after a bout of flu or another upper respiratory infection. The child may refuse to stand on their feet or crawl. This condition is usually benign and resolves on its own.
• Injuries: Strains and bruises sustained during falls as the child learns to sit, crawl, and walk.
• Reaction to vaccination: Thigh muscle pain is an expected local reaction to the injection.

If the pain is severe, accompanied by high fever, swelling, or pronounced muscle weakness, a doctor should be consulted to rule out more serious conditions such as bacterial myositis. For general mechanisms, read the article "Muscle pain".