Diagnosing Beyond Bias: Differentiating Topical Steroid Withdrawal Syndrome From irAE-Induced Adrenal Insufficiency.

Confirmation bias can impede accurate diagnosis. Since the approval of immune checkpoint inhibitors (ICIs), physicians are on high alert for newly developed immune-related adverse events (irAEs). Therefore, when patients present irAE-like symptoms, there is a risk of confirmation bias leading to overlooked diagnoses. This paper discusses a case of a patient with non-small cell lung cancer treated with nivolumab and topical dexamethasone ointment for an extended period due to oral mucocutaneous irAE. The patient developed adrenal insufficiency, initially considered to be a likely case of pituitary irAE. However, further investigation and the patient's clinical course revealed an unexpected diagnosis more in line with topical steroid withdrawal syndrome.