Azathioprine-induced fever in sarcoidosis

To report a case of drug-induced fever associated with azathioprine treatment in a patient with sarcoidosis.

A 52-year-old man with pulmonary sarcoidosis presented to the emergency department with a 1-day history of fever (temperature 39.9 °C), chills, nausea, and vomiting. One week earlier, azathioprine 50 mg/day had been started for worsening dyspnea. The patient was admitted and evaluated for acute infectious processes. All of his home medications (hydroxychloroquine, prednisone, fluticasone/salmeterol, lovastatin, pantoprazole, zolpidem, ibandronate, albuterol), except prednisone, were held. Results of chest X-ray, viral cultures, and urine and blood cultures revealed no source of infection. The patient's temperature returned to normal within 30 hours after discontinuation of azathioprine; rechallenge was not performed.

Fever as an adverse drug reaction is often unrecognized, particularly in medically complex patients. Azathioprine has been reported to cause drug fever in patients with inflammatory bowel disease and in those with rheumatoid arthritis; to our knowledge, there have been no previous reports documenting azathioprine-induced fever in patients with sarcoidosis. The chronological course of febrile response and defervescence is highly suggestive of drug-induced fever.

The rapid resolution of fever after discontinuation of azathioprine suggests that it was the likely source of fever in this patient. If azathioprine is increasingly prescribed in patients with sarcoidosis, fever as an adverse reaction may become more common.