Types of Acute Arthritis 

Acute Inflammatory Arthritis 

Acute inflammatory arthritis refers to a group of diseases triggered by an overactive immune system that typically attacks several joints at the same time. Getting diagnosed and treated early is essential to preventing this type of arthritis from becoming a chronic condition. While exact incidence is unknown, it is less common than other types of arthritis, such as osteoarthritis.

Symptoms of acute inflammatory arthritis include:

Joint pain and stiffness after periods of rest or inactivity, particularly in the morning, lasting about an hourSwelling, redness, and warmth in the affected joints

Treatments for this condition usually include:

Nonsteroidal anti-inflammatory medications (NSAIDs) or corticosteroids to reduce symptoms Physical or occupational therapy to improve outcome

Septic Arthritis 

Septic arthritis refers to joint infection caused by bacteria, viruses, fungi, or parasites. Bacteria are the most common cause and most serious due to its highly destructive nature. Incidence varies in the United States, causing between two to 10 cases per 100,000 people.

Signs of septic arthritis include:

FeverFeeling unwell or malaisePain in the affected jointWarmth in the affected jointSwelling (effusion) in the affected jointDecreased range of motion in the affected joint

Treatments for septic arthritis can include:

Antibiotics to kill bacteria (if caused by bacteria) Antifungal medication (if caused by fungal infection) Drainage of the affected joint using a needle, tube, or surgery (joint aspiration) Medications such as NSAIDs to treat other symptoms, including fever and pain Splints to relieve joint pain

Gout

Gout is an extremely painful condition caused by a buildup of uric acid crystals in the joints. This buildup occurs when there is too much uric acid in your body, a condition known as hyperuricemia. The body makes uric acid when it breaks down purines, which are found in your body and the foods you eat. When there is too much uric acid in the body, uric acid crystals (monosodium urate) can build up in joints, fluids, and tissues within the body.

Research shows increased risk of mortality in the following cases:

Hip infection Shoulder infection Multi-site infection Being male Comorbidities Age over 65

Gout usually affects one joint at a time, most commonly the big toe joint. The incidence of gout among adults in the United States is 3.9%.

The symptoms of gout include:

Pain, usually intenseSwellingRednessHeat

Common treatments include:

NSAIDs or corticosteroids Colcrys (colchicine) Medications that help lower uric acid levels, including Zyloprim (allopurinol) and Uloric (febuxostat)

Bacterial Arthritis 

Bacterial arthritis develops over hours or days. It is categorized as either gonococcal or nongonococcal. The two main differences are that the gonococcal type is caused by the spread of the gonorrhea bacteria and nongonococcal infections are not, and that gonococcal infections are far less destructive to the joint.

Symptoms of gonococcal arthritis include:

Fever Tendon inflammation Painless lesions (papules, pustules, or macules) on the arms and legs Single joint arthritis (monoarticular) Areas typically affected are the knees, ankles, and wrists.

Symptoms of nongonococcal arthritis include:

Moderate to severe joint pain that worsens with movementInfected joints are swollen, red, and warm. Low-grade feverAreas affected are typically the knees, hips, wrists, ankles, or elbow joints.

Treatments used for infectious arthritis include:

Antibiotics such as azithromycin and ceftriaxone Pus drainage from infected joints

Evaluation and Diagnostic Tests: What to Expect

If acute arthritis is suspected, your healthcare provider will examine the area of concern and check for tenderness, swelling, redness, and other obvious signs of the disease. They will ask about your medical history, including any family history of arthritis, and questions about when your symptoms first started and how they’re affecting your everyday activities.

After the physical exam, your healthcare provider will order a blood panel and urine test to check for the markers of arthritis and rule out other conditions that may be contributing to or causing your symptoms.

Complete Blood Cell Count (CBC)

A complete blood count checks your red and white blood cells to look for signs of inflammation and infection. It will also include a platelet count and hemoglobin and hematocrit tests to check for anemia.

Synovial Fluid Exam

Synovial fluid provides cushion and lubrication for joints. It will be extracted from the affected joints and examined for markers of infection and inflammation. For example, the total white blood cell (WBC) count will be elevated in the presence of an infection. The WBC count will also measure the percentage of polymorphonuclear leukocytes count (PMN). In an acutely infected joint, the PMN count will be greater than 95%.

Fluid is also checked for uric acid crystals and will be tested for the presence of bacteria and fungi (and sometimes, viruses).

Molecular Testing

Molecular testing like polymerase chain reaction testing can be used to detect organisms in clinical samples. For example, your healthcare provider may order a nucleic acid amplification test (NAAT) to check for gonococci bacteria. Specimens can be collected from the cervix, urethra, throat, or rectum.

Uric Acid Test

A uric acid test measures the amount of uric acid in your blood or urine. It helps diagnose gout.

Several risk factors can increase your likelihood of having acute arthritis. Some of these risk factors (like age) are out of your control. Others can be controlled with lifestyle modifications.

In some cases, having one form of arthritis increases your likelihood of developing acute arthritis. A common example is rheumatoid arthritis and other disorders causing chronic joint damage. These diseases significantly increase one’s risk of infectious arthritis, particularly bacterial arthritis.

Other risk factors include:

Advanced age (over 60) Cancer and chemotherapy Chronic illness such as lung or liver disease Diabetes Having a prosthetic joint High-purine diet History of joint infection or joint surgery Injection drug use Immunodeficiencies, including HIV infection Immunosuppressive therapies, including corticosteroids Gonorrhea Lupus Sickle cell disease Skin infections Risk factors associated with sexual disease transmission

Note that these risk factors are strongly associated with immune system functioning and immune suppression and likelihood of exposure to organisms that cause infection. For example, exposure to ticks carrying Borrelia burgdorferi (the cause of Lyme disease) can increase your risk of acute infectious arthritis. If you notice localized redness, swelling, or signs of infection, contact your healthcare provider immediately.

A Word From Verywell

Even if you’ve been diagnosed with a chronic form of arthritis, you should always discuss any new or sudden onset of joint pain, tenderness, or swelling to rule out acute arthritis. With accurate diagnosis comes proper treatment, you will feel better and return to regular activity sooner rather than later.