Signs of Pyomyositis (Muscle infection)

Description

A bacterial infection of the muscle. The most common bacteria is Staphylococcus with Methicillin Resistant Staphylococcus Aureus (MRSA) becoming more common. The disorder usually begins as an infection in the blood stream that spreads to the muscle. Traumatic injury of the muscle increases the likelihood of this disease. Three fourths of all patients have a weakened immune system either from disease such as HIV or from medications such as chemotherapy. Pyomyositis is most often seen in children aged 2-5 but this order can occur in any age group. The muscles of the pelvis and legs are most commonly affected. The disease is more commonly encountered in tropical regions. Left untreated the infection can involve other organs and lead to death (sepsis).

Symptoms

Fever, pain in the affected muscle, tenderness, muscle swelling, problems walking if the pelvis or legs are involved. Later in the course redness of the skin and increased warmth of the skin may occur. Low blood pressure, fainting, confusion and death can occur if the infection is untreated.

Tests

A history and physical exam will be done. A MRI is the best test to confirm the diagnosis. A CT scan can also be used. Blood tests such as a complete blood count (CBC) and blood cultures may be performed.

Standard Workup

CT Scan
MRI

Treatment

Broad spectrum intravenous antibiotics with coverage against MRSA is given. If a collection of pus (abscess) is present or the bone is involved surgery is needed to remove the infected tissue.