• 20% do not have a family history
• An androgen-dependent trait

• Family history of alopecia
• Patients often give a history of emotional trauma/stress prior to its onset
• Usually rapid hair loss in a well-defined, typically round area
• Patients complain of 1-4 cm² of hair loss on the scalp
  • Patch is usually clean-looking without scaling
• May be asymptomatic, but some patients experience paresthesias with pruritus, burning sensation, pain or tenderness prior to loss of hair

Androgenic alopecia in men/women

• Rarely indicated for MPHL and women with normal menstrual cycle
• If with evidence of androgen excess in FPHL, consider Total testosterone, free testosterone, DHEA-S, prolactin levels
• If without evidence of androgen excess: Rule out thyroid disease, syphilis, Fe deficiency and Systematic Lupus Erythematosus (SLE) as cause of hair loss
• Biopsy is sometimes necessary for FPHL to exclude chronic telogen effluvium, diffuse alopecia areata or cicatricial hair loss
• Hair pull positive in active early hair loss but negative in long standing hair loss

Alopecia areata

• Diagnosis is usually clinical
• Hair pull test may be positive at the margins which is indicative of active disease
• Patch biopsy of the scalp in rare difficult cases
• Thyroid Stimulating Hormone (TSH) hormone level determination is routinely performed by many physicians to rule out any related thyroid abnormality