The patient, Wang Mou, male, 20 years old, was admitted to the hospital with the complaint of “intermittent fever for more than 7 months”. 7 months ago, the fever appeared without any obvious cause, with a maximum temperature of 39.6 degrees, accompanied by chilliness, sore throat, papules in both quarters, without itching and pain, without nausea, vomiting, headache, cough and sputum, and was treated with infusion at a local clinic (details unknown). 8 days ago, he was diagnosed with “rheumatic fever” and was hospitalized, given cefadroxil 2.0 every 12 hours for 7 days, and levofloxacin 0.3 once a day for 5 days, along with diflucan and dexamethasone. He was admitted to our department with “fever to be investigated”. He was admitted to our department with “fever to be investigated”. He was mentally well, had poor diet, poor sleep, normal stools, slightly yellow urine, and no significant weight loss. He was admitted to our department with “fever to be investigated”. The remaining superficial lymph nodes were not enlarged. The lips were red, the pharynx was less red, the tonsils were not large, the tongue was stretched out in the middle, the neck was soft, the thyroid gland was not large, the sternum had no pressure pain and percussion pain, the respiratory sounds of both lungs were clear, no dry and wet large was heard 96 times/minute, the rhythm was uniform, no pathological murmur was heard in each valve auscultation area, the abdomen was slightly tender, there was no pressure pain in the whole abdomen, no rebound pain, the liver and spleen were not touched under the ribs, the intestinal sounds were normal, there was no edema in both lower limbs. Physiological reflexes were present and pathological reflexes were not elicited. Auxiliary examinations: 1. routine blood WBC1.22X10*9/LPLT130X10*9/LHB122g/L neutrophil 60% lymphatic 40%, 2. chest X-ray with enhanced texture in both lungs, 3. typhoid and paratyphoid antigen detection: negative, 4. rheumatic and rheumatoid factors negative, bone marrow sampling partially diluted, bone marrow with hyponuclear cells, no special cells detected, no parasites detected. Preliminary diagnosis of fever cause to be investigated systemic lupus erythematosus adult Still disease lymphoma tuberculous peritonitis typhoid fever.