Alopecia is the absence or loss of hair in an area where it is expected to be present. This condition can be localized or diffuse, temporary or permanent, and affect both sexes and all age groups. Recognized as a sign or symptom arising from heterogeneous etiologies, alopecia is broadly classified as nonscarring (the most prevalent) and scarring (cicatricial). Patients may present with significant distress, diminishing their quality of life. A detailed history, physical examination, and focused evaluation are necessary to determine the underlying cause, which will guide the decision-making process for the most appropriate management for the best outcomes. Of note, the nomenclature in the literature typically uses nonscarring rather than noncicatricial and varies between scarring and cicatricial. This review uses nonscarring and scarring for simplicity, except when cicatricial is part of the named disorder.
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