A rare primary Candida parapsilosis infection of the knee joint in a patient without predisposing factors: A case report

RATIONAL: Knee joint infection caused by isolated primary Candida is extremely rare, with only a few cases reported. It occurs most often in patients with predisposing factors (e.g., immunosuppression, malignancy, drug abuse) or fungal invasion during traumatic procedures, including surgery. We report an unusual case of Candida parapsilosis infection in the knee joint with no predisposing factors. PATIENT CONCERNS: A 65-year-old man entered our hospital complaining of persistent pain and mild swelling of the right knee that seriously affected normal walking. There was no obvious cause for his distress. DIAGNOSIS: The case was eventually diagnosed as a primary Candida parapsilosis infection which had many diagnostic particularities and difficulties. INTERVENTIONS: Total knee arthroplasty (TKA) was ultimately performed followed by fluconazole coverage. OUTCOMES: The patient showed good clinical performance at the 3- and 6-month follow-up visits and was very satisfied with the therapeutic effect. LESSONS: If there were suspected symptoms of primary Candida infection cases, imaging and microscopic examinations, tissue cultures, and pathological examination of the puncture knee joint fluid were required.