What condition is caused by bacterial infection primarily in long bones?

Osteomyelitis is a condition characterized by an infection of the bone, often caused by bacteria. This infection can occur in any bone but is most commonly found in the long bones, such as the femur and tibia. The bacteria can reach the bone through the bloodstream, from nearby infected tissue, or following an injury or surgery that exposes the bone to infection.

In osteomyelitis, the bacteria cause inflammation and can lead to the death of bone tissue if not treated adequately, which can result in significant morbidity. Symptoms often include localized pain, fever, swelling, and redness in the affected area.

Other options represent different conditions that do not primarily affect the bone itself. Periostitis involves inflammation of the periosteum (the connective tissue surrounding bones), while necrotizing fasciitis is a severe soft tissue infection. Rheumatoid arthritis is an autoimmune condition that affects the joints and can cause bone erosion, but it is not directly caused by a bacterial infection.