Reactive Arthritis Diagnosis

Your provider will likely begin to diagnose^[17] reactive arthritis by asking about your signs and symptoms. If your reactive arthritis was triggered by a gastrointestinal infection, digestive symptoms, such as diarrhea, typically dissipate before arthritis symptoms begin. On average, genitourinary infection symptoms usually precede reactive arthritis symptoms by about two weeks. Because reactive arthritis is common^[18] in people with HIV, your provider may run a blood test to rule out HIV in the process of your diagnosis. A notable symptom of reactive arthritis in people with HIV is psoriasiform dermatitis, a severe type of skin inflammation on the palms, scalp, and soles of the feet. Your healthcare provider may ask about your overall health and perform a physical exam to check for signs^[19] of joint inflammation, skin rashes or discoloration, signs of eye infection, reduced range of motion in your spine and affected joints, and warmth or tenderness at sites of inflammation. This exam may also include lab testing, including blood tests used to check for:

• Inflammatory markers in the blood (such as erythrocyte sedimentation rate)
• Evidence of a past or present infection (may also be indicated by stool samples or urine samples)
• Presence of antibodies known to be associated with other forms of arthritis
• The genetic marker HLA-B27

Your healthcare provider may order additional tests to supplement the information gathered from your physical exam and blood tests. X-rays of the knees, feet, ankles, or back can detect the presence of reactive arthritis and rule out other forms of arthritis as the cause of your signs and symptoms. A sample of fluid from the affected joint may also be tested for signs of an infection or the presence of other conditions, including septic arthritis or gout.