A patient with Crohn's disease is prescribed azathioprine. Which finding would concern the nurse that the patient is experiencing a serious side effect of the medication?

A new reported temperature of 99.2 degrees Fahrenheit

The patient reports 3 episodes of diarrhea over the last week

Dry cough when waking up in the morning

Alanine aminotransferase (ALT) 65 units (reference range: 5-35 units)