An infection of a joint most frequently caused by bacteria (although fungi, parasites, and mycobacteria may also rarely cause this infection). See also knee septic arthritis.
This infection occurs most commonly as a result of hematogenous seeding of the joint in the setting of bacteremia. A joint may be inadvertently inoculated with a pathogen at the time of surgery or trauma. In some patients, a severe soft tissue infection may spread to involve a nearby joint.
Common pathogens responsible for this infection include Staphylococcus aureus, Streptococcus species, gram-negative bacilli, and Neisseria gonorrhoeae.
Risk factors for this infection include old age, diabetes mellitus, recent joint surgery or procedure, skin infection, the presence of a prosthetic joint, or immunosuppression. Patients with rheumatoid arthritis or who abuse intravenous (IV) drugs are also at increased risk for this infection.
Patients present with a swollen, warm, stiff, and painful joint. Fever may be present. The majority of the time, a single joint (usually the knee) is involved. Symptoms develop over 1-2 weeks. If the infection is caused by N gonorrhoeae, patients classically also present with a rash and tenosynovitis. If the infection is due to fungi or mycobacteria, the symptoms may be subtler and may worsen more gradually.
Diagnosis can be made by arthrocentesis. Joint fluid should be sent for analysis including cell count, microscopic analysis for crystals, Gram stain, and bacterial culture. Additional cultures of the joint fluid can be obtained if an atypical pathogen is suspected by history or examination.
Treatment requires drainage of the joint (surgically or by repeated needle aspiration) in combination with antimicrobial therapy.
Codes
ICD10CM: M00.80 – Arthritis due to other bacteria, unspecified joint
Lyme arthritis – May present with similar symptoms as septic arthritis, but usually with less pain. Serologic testing for Lyme disease may be performed in patients with a possible exposure history. Arthrocentesis to exclude septic arthritis due to typical pathogens should still be performed.
Rheumatoid arthritis – Classically presents with symmetrical involvement of peripheral joints.
Gout – Intracellular urate crystals seen in joint fluid (presence of crystals does not rule out concomitant septic arthritis).
Calcium pyrophosphate deposition disease – Calcium pyrophosphate crystals seen in joint fluid (presence of crystals does not rule out concomitant septic arthritis).
Reactive arthritis – Patients have a preceding illness (eg, diarrhea or urethritis) and may also present with enthesitis, dactylitis, or inflammatory back pain.
Osteoarthritis – Usually symptoms are chronic and there are not usually inflammatory findings (red, hot, swollen joint) on examination.
Injury (eg, meniscal tear) – Patient will usually relate a history of preceding trauma.
Hemarthrosis – Patient will usually have a history of trauma or a bleeding disorder.
Septic arthritis is an infection of a joint and requires immediate attention. The infection can arise from germs entering your bloodstream from other parts of your body. Septic arthritis can also occur after an injury where germs can enter the joint directly. Septic arthritis most commonly occurs in the knees, but it can also occur in other joints including the hips and shoulders.
Who’s At Risk
Septic arthritis is caused by viral, bacterial, or fungal infections. Staphylococcus aureus (staph) is the most common type of infection.
Although septic arthritis usually occurs after an illness, germs can enter the joint due to puncture wounds, surgery, or drug injections.
Some risk factors for septic arthritis are:
Chronic joint problems
Rheumatoid arthritis medication
Fragile skin
Joint trauma
Signs & Symptoms
Septic arthritis causes sudden pain, discomfort, and difficulty moving the affected joint. The joint may appear red and swollen. The joint may feel warm, and you may have a fever.
Self-Care Guidelines
Once you have seen your health care provider, follow your health care provider's instructions to help you clear the infection. Take antibiotics for the full time instructed.
When to Seek Medical Care
Contact your health care provider immediately if you have sudden pain in one of your joints and suspect you have a bacterial infection.
Treatments
If you have an active bacterial infection, your doctor will prescribe antibiotics. Severe infection with bacteria resistant to antibiotics may require you to stay in the hospital to be given IV antibiotics. You may also need anti-inflammatory medicine.
Your doctor will evaluate your joint to see if it needs to be drained of fluid. Depending on the type of joint and the severity of the infection, your health care provider may remove the fluid either by a needle or by open surgery, which is commonly used for infections of the hips.
Coronal CT view demonstrates large right hip joint effusion with foci of air and erosion of the femoral head and acetabulum. Findings are consistent with septic arthritis with associated osteomyelitis. Note that the femoral head is dislocated due to the underlying effusion and infection.
Patient Information for Septic arthritis