Fever in a patient with mild acute pancreatitis caused by ulinastatin injection: A case report

RATIONALE: The case describes a patient with mild acute pancreatitis (AP) who developed a persistent high fever during ulinastatin treatment. This highlights the possibility of drug-induced fever, which is a rare but important adverse reaction of ulinastatin and is often overlooked in clinical practice. PATIENT CONCERNS: A 58-year-old male patient with mild AP had a persistent high fever during the treatment with ulinastatin, but there was no evidence of infection. DIAGNOSES: Mild AP, ulinastatin-related drug fever. INTERVENTIONS: The initial conservative treatment for AP included fasting, rehydration and taking ulinastatin. Antibiotics (ceftriaxone, later changed to imipenem) were used for suspected infection. After excluding infection, ulinastatin was discontinued. OUTCOMES: Within 48 hours of stopping ulinastatin, the patient's fever symptoms were relieved and his subsequent condition stabilized. LESSONS: This case highlights the importance of considering drug-induced fever in clinical practice. Recognizing it promptly and discontinuing the drug can prevent unnecessary interventions and improve outcomes.