Still’s disease originally referred to juvenile-onset chronic arthritis with systemic onset, but a similar disease can occur in adults and is called adult onset Still’s disease (AOSD). The cause of the disease is unknown. It is characterized clinically by fever, arthralgia and/or arthritis, rash, neutrophilia, and in severe cases, systemic damage. Diagnosis and differential diagnosis are difficult because there are no specific diagnostic methods or criteria. The following are the main symptoms and signs of the disease 1, fever: the most common and earliest symptom of the disease. more than 80% of the patients have a typical flaccid fever, and the body temperature often reaches 39 ℃ or more. 2, skin rash: the disease is the most common and earliest symptom. 2, rash: is another major manifestation of the disease, about 85% of the patients below, the typical rash is orange-red macular rash or maculopapular rash. Sometimes the form of the rash is variable, and can be urticaria-like rash. The rash is mainly distributed on the trunk, limbs, but also can be seen on the face. The rash is often accompanied by fever, often in the evening when the fever began to appear, the next morning after the fever disappeared, the rash also disappeared. 3, joint and muscle symptoms: almost 100% of patients have joint pain, arthritis in more than 90%. Knee and wrist joints are most often involved, followed by ankle, shoulder and elbow joints, proximal interphalangeal joints, metacarpophalangeal joints and distal interphalangeal joints can also be involved. In the early stage of the disease, few joints are involved, but later it may increase to polyarthritis. In many patients, the cartilage and bone tissues of the affected joints may be damaged by erosion, so joint stiffness and deformity may occur in the late stage. Muscle pain is common, accounting for more than 80%. Most patients have different degrees of muscle pain when they have fever, and some patients have muscle weakness and mildly increased muscle enzymes. 4, sore throat: most patients have sore throat in the early stage of the disease, sometimes present throughout the course of the disease, sore throat appears or worsens during fever. It is relieved after the fever subsides. There may be pharyngeal congestion, lymphoid follicular hyperplasia in the posterior pharyngeal wall and enlarged tonsils, negative culture of pharyngeal swab and ineffective antibiotic treatment. 5.Other clinical manifestations: there may be peripheral lymph node enlargement, hepatosplenomegaly, abdominal pain (a few seem to be acute abdomen), pleurisy, pericardial effusion, myocarditis and pneumonia. Less common are renal damage, central nervous system abnormalities, and peripheral nervous system damage. In a few patients, acute respiratory failure, congestive heart failure, pericardial tamponade, constrictive pericarditis, diffuse intravascular coagulation, severe anemia, and necrotizing lymphadenopathy may occur.