Laboratory Tests and Ancillaries
Androgenic Alopecia in Males/Females
It must be noted that diagnostic tests are rarely indicated for MPHL and females with normal menstrual cycles. If there is evidence of androgen excess in FPHL, total testosterone, free testosterone, dehydroepiandrosterone sulfate (DHEAS), prolactin levels can be considered. If there is no evidence of androgen excess, thyroid disease, syphilis, iron deficiency, and systemic lupus erythematosus (SLE) are ruled out as possible cause of hair loss. Biopsy may be necessary at times 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. In trichoscopy, features typical for androgenic alopecia include vellus hairs >10%, increased percentage of follicular units with only one hair shaft, hair shaft thickness heterogeneity of ≥20%, yellow dots, perifollicular discoloration, empty follicles, and circle hair and honeycomb pigment pattern.
Alopecia Areata
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 may be done in rare difficult cases. Thyroid stimulating hormone (TSH) level determination is routinely performed by many physicians to rule out any related thyroid abnormality.
Alopecia_Diagnostics
Imaging
Medical photography is recommended to be done in alopecia areata for a baseline.