An intramuscular gluteal abscess is an intramuscular soft tissue lesion of the gluteal region characterized by inflammation and the collection of pus, often at the site of intramuscular injections or adjacent to subcutaneous infection sites such as epidural abscess or psoas abscess. Signs and symptoms include tenderness, warmth, pain, erythema, and swelling. For a deep-seated abscess, swelling may be the only symptom, or it may be accompanied by pain and tenderness.

The cause of the abscess is typically bacterial, such as Staphylococcus aureus or strains of Streptococcus. Introduction of bacteria into muscle can occur during intramuscular injections such as glucocorticoids into the gluteal muscle to treat rheumatoid arthritis, immune globulin treatments, antipsychotic drug injection, and in opioid use disorder treatments.

The abscess may be complicated by the presence of comorbid conditions (diabetes, human immunodeficiency virus disease) or co-infection (folliculitis, cellulitis).

Otherwise healthy individuals may come into contact with bacteria such as methicillin-resistant S. aureus (MRSA), particularly community-acquired MRSA (CA-MRSA), from other infected persons, in a hospital setting, during recent surgery, while incarcerated, or in a long-term care facility. Other opportunities to acquire pathogens include IV drug use, shared needles, military service, and contact sports.

Management involves incision, drainage, packing, and appropriate wound care. A course of antibiotics may be utilized when infection is severe and to minimize recurrence of the abscess or spread of infection to adjacent tissue. A high degree of caution is advised to avoid the spread of CA-MRSA during procedures in the health care setting.