Septic (infective) arthritis occurs when bacteria — or, less commonly, other organisms — infect a joint, causing rapid and severe inflammation. Unlike the other chronic conditions on this site, septic arthritis is an acute medical emergency that can permanently destroy a joint within days if not treated urgently.

• It typically affects a single joint — most often the knee — that becomes severely swollen, hot, red and extremely painful very quickly, usually over hours to a couple of days.
• It is often accompanied by fever and a general feeling of being unwell.
• People with an already-damaged joint (from rheumatoid arthritis or a previous joint replacement), a weakened immune system, diabetes, or intravenous drug use are at higher risk.
• Delay in treatment can permanently destroy the joint cartilage within as little as 24–48 hours — this is why septic arthritis is treated as a same-day emergency, not a routine consultation.

• Sudden, severe swelling, warmth and redness of a single joint (most often the knee, hip, wrist or ankle)
• Intense pain, often making it impossible to move the joint or bear weight on it at all
• Fever, chills and feeling generally unwell
• Rapid worsening over hours to a day or two, unlike the slower onset of most other types of arthritis
• In infants, elderly patients or those on immunosuppressive treatment, symptoms can sometimes be less obvious — a lower threshold for concern is needed in these groups

• Bacteria most commonly reach the joint through the bloodstream from an infection elsewhere in the body, or are introduced directly through a wound, injection or surgery near the joint.
• Staphylococcus aureus is the most common cause in adults, though many other bacteria — and occasionally fungi — can be responsible.
• Risk is higher in joints already damaged by rheumatoid arthritis, osteoarthritis or a previous joint replacement.
• People with diabetes, a weakened immune system (including those on immunosuppressive treatment for another rheumatic disease), or intravenous drug use are at increased risk.

• Urgent clinical assessment — this diagnosis should never be delayed for a routine appointment slot.
• Joint aspiration (arthrocentesis) — fluid is drawn from the joint with a needle and sent urgently for testing; this is both the key diagnostic test and provides immediate symptom relief.
• Joint fluid analysis for white cell count, Gram stain and culture to identify the causative organism and guide antibiotic choice.
• Blood tests (blood count, inflammation markers, blood cultures) and imaging as needed to assess the extent of infection.

Urgent joint drainage

The infected joint fluid is drained urgently — sometimes repeatedly over the following days — to remove infection and reduce pressure and damage inside the joint. In some cases, surgical washout is needed.

Intravenous antibiotics

Antibiotic treatment usually starts intravenously in hospital as soon as joint fluid has been sent for testing, without waiting for results, and is then adjusted once the specific organism is identified. Treatment typically continues for several weeks.

Close monitoring and rehabilitation

Once the infection is controlled, physiotherapy helps restore joint movement and strength, and follow-up monitoring checks that the infection has fully cleared and assesses any residual joint damage.

This condition cannot be safely evaluated through a routine scheduled visit. Please call us directly for urgent guidance. Consultations with the OARC rheumatology team otherwise run Monday to Saturday, 9:00 AM–2:00 PM and 4:30–9:00 PM. Call +91 93386 53086.

• With prompt drainage and antibiotic treatment, most patients recover well and preserve normal joint function.
• Delayed treatment is the single biggest risk factor for permanent joint damage — cartilage can be irreversibly destroyed within 24–48 hours of infection taking hold.
• After recovery, some patients — particularly those with a pre-existing joint condition — need ongoing rheumatology follow-up to manage the underlying joint disease and reduce the risk of future infection.