Ankle swelling is a common presenting symptom, especially in active toddlers who are learning to walk and in adolescents involved in sports. In children, the swelling is often noticed after the child starts limping or complaining of general symptoms, and close inspection reveals the swelling. There are several potential causes of ankle swelling, and it is important to distinguish them because they could be represent serious illness.
Children are the most common age group to suffer from joint infections. Both bacteria and viruses can cause infections in the ankle's joint space. There is also a condition called postinfectious arthritis, in which children have swelling of a joint several days or weeks after a previous, seemingly mild viral illness.
Ankle swelling is usually painful and accompanied by other signs like fever and redness if it's caused by an infection. Decreased range of motion of the ankle and the foot may be related to trauma or systemic illness.
There are two important tests or procedures that are important in the diagnosis of ankle swelling. X-rays are necessary for the diagnosis of ankle fractures. In children, fractures can extend through the bone's growth plate. These fractures often require surgical intervention to prevent future disability and complications. The other important procedure is a joint aspiration, in which a needle is introduced in the joint space to withdraw fluid. This fluid can be evaluated for the presence of bacteria and other markers of infection.
There are several inflammatory conditions that can cause ankle swelling. Juvenile idiopathic arthritis, or JIA, is an inflammatory condition that presents with swelling of at least two joints, one of which can be the ankle. In JIA, the ankle can be painful and red and feel warm. Children can have stiffness of the ankle, especially in the morning, and can have a salmon-colored rash and frequent fever spikes. Another systemic illness that can cause ankle swelling is Henoch-Schönlein Purpura, or HSP. This is an inflammatory condition that presents with patches of bruises on the legs, abdominal pain and joint swelling.
Septic joint, or bacterial infection of a joint, is considered a medical emergency that needs prompt fluid drainage for identification of the bacteria and intravenous antibiotic therapy. Another potentially serious infection that needs prompt medical attention is osteomyelitis, or infection of the bones in the ankle.
- NIH Medline Plus: Foot, Leg, and Ankle Swelling
- "Comprehensive Pediatric Hospital Medicine"; Lisa Zaoutis and Vincent Chang; 2007