Alopecia Diagnosis

• Some 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 males/females

• Rarely indicated for MPHL and females with normal menstrual cycle
• Include pull test and examination of facial and body hair and nails
  • Pull test must be performed in the right and left parietal areas, frontal and occipital areas and in visibly affected areas
    • Hair pull test is positive in active early hair loss but negative in long standing hair loss

• If with evidence of androgen excess in FPHL, consider total testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEAS), prolactin levels
• If without evidence of androgen excess: Rule out thyroid disease, syphilis, iron 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
• Trichoscopy (also known as dermoscopy) should be considered in doubtful cases
  • Features typical for androgenic alopecia include vellus hairs >10%, increased percentage of follicular units with only 1 hair shaft, hair shaft thickness heterogeneity of ≥20%, yellow dots, perifollicular discoloration, empty follicles, circle hair and honey comb pigment pattern

Alopecia areata

• Diagnosis is usually clinical
• Hair pull test may be positive at the margins which is indicative of active disease
• Trichoscopy (dermoscopy) may be helpful for visualizing findings consistent with alopecia areata
  • Features typical of alopecia areata include short vellus hairs, black dots, yellow dots, tapering hairs and broken hairs

• Patch biopsy of the scalp in rare difficult cases
• Thyroid stimulating hormone (TSH) level determination is routinely performed by many physicians to rule out any related thyroid abnormality