Arthritis caused by infection: A case report.

Cryptococcal infections are uncommon in individuals with normal immune functions. These infections commonly affect the lungs and central nervous system; however, there are a few reports of infection in the bone and joint areas. The current study reported a case of knee joint infection caused by in China. A 56-year-old man presented to The China Academy of Chinese Medical Sciences Guang'anmen Hospital Baoding Hospital (Baoding, China) with severe anemia and lung inflammation. Initially, there was no obvious cause of swelling or pain in the knee joints. However, after the patient presented with new swollen and painful knee joint symptoms, pus culture and cryptococcal antigen detection tests confirmed infection. After pus drainage and fluconazole treatment, the patient's condition substantially improved. Clinical awareness of infections should be promoted. In suspected cases, puncture fluid or tissue pathogen testing should be performed as early as possible to avoid misdiagnosis and serious consequences of delayed treatment.