Hair loss: A systematic approach to evaluation, diagnosis, and management.

Hair loss (alopecia) is a common presentation in both primary care and dermatology. It often signals underlying inflammation or abnormalities in hair cycling or hair shaft structure, requiring a thorough and systematic evaluation. Clinical guidelines emphasize pattern recognition, trigger identification, and targeted interventions. This article equips physician associates (PAs) with an evidence-based approach to assessing patient history, conducting physical examinations, selecting appropriate diagnostics, and implementing treatment strategies for alopecia. History and scalp inspection guide diagnosis, with the differential including such conditions as telogen effluvium (diffuse), alopecia areata (focal), and androgenetic alopecia (patterned). Recommended laboratory tests include thyroid-stimulating hormone, complete blood cell count, and iron studies, while scalp biopsy is used to confirm scarring. Treatments address causes, with avoidance of triggers central to effluvium, intralesional steroids or baricitinib for alopecia areata, minoxidil-based therapy for androgenetic alopecia, and antifungals for tinea capitis. By integrating trichoscopy, selective testing, and etiology-specific care, PAs can enhance diagnostic accuracy and optimize outcomes for patients with hair loss.