Diagnostic challenges in determining alopecia areata

Alopecia areata (AA) is the second most common cause of hair loss. It is crucial for the clinician to differentiate AA from other types of hair loss as it differs in prognosis and treatment. The diagnosis of AA can be made clinically; however, there are many nuances making an exact diagnosis challenging. This paper describes the differential diagnoses of both scarring and non-scarring hair loss that may mimic AA. It also highlights the diagnostic tests and pertinent findings that help distinguish AA from other types of hair loss.