Have you ever heard of reactive arthritis? Anyone who knows about this disease should know that it is a systemic disease with acute onset and different clinical manifestations. For the symptoms of reactive arthritis, 1. Common systemic symptoms are fatigue, general malaise, myalgia and low fever. A few patients may have moderate fever. 2. Joint symptoms Reactive arthritis is mainly characterized by joint involvement to varying degrees. Mild people may only feel joint pain, and severe people may have obvious polyarthritis and even limited activities. The typical manifestation is that the single joint is asymmetric or arthritis is less and gradually aggravated, and the joints of lower limbs are most commonly involved, such as knees, ankles and hips. Shoulder, elbow, wrist and small joints of hands and feet can also be involved. There is local redness, pain, skin temperature rise or skin erythema. Sausage toe of foot facet joint is more common. Some patients may have lower back and sacroiliac joint pain. 3. Tendonitis is one of the common symptoms of reactive arthritis. It is characterized by local pain and tenderness of tendon at the attachment point of bone. Achilles tendon, plantar tendon, patellar tendon attachment point and paraspinal tendon are the most easily involved. In severe cases, limited activity or muscle apraxia may occur due to local pain. 4. Skin mucosal skin mucosal lesions are more common in reactive arthritis. The most typical manifestation is purulent keratosis of palms and soles. This kind of skin damage and the coarseness and thickening of nails in some patients can be similar to the skin manifestations of psoriasis. Mainly seen in gonococcal infection and other reactive arthritis after sexual intercourse, other types of reactive arthritis are rare, and the reasons are not clear. Some patients with reactive arthritis may have whirlpool balanitis, cystitis and prostatitis, which are characterized by frequent urination, urgency, dysuria and hematuria. In female patients, cervicitis and salpingitis may still occur. Erythema nodosa is only found in some patients, mainly Yersinia infection. Clinical studies have found that the expression of HLA-B27 may have nothing to do with erythema nodosum. Oral ulcer is another common manifestation of reactive arthritis, mostly superficial painless small ulcer, which can occur in the mucosa of palate, tongue margin, lip and cheek.