Trichoscopy: Essentials for the dermatologist

Figure 1 Male androgenetic alopecia. Hair shaft thickness heterogeneity and predominance of follicular units with only one hair (Dermlite photo^®).

Figure 2 Female androgenetic alopecia. Significant (> 20%) diversity of hair shaft diameter. Note also yellow dots. Higher hair density and less variability in the occipital area (B) compared to the frontal area (A) (Dermlite photo^®).

Figure 3 Alopecia areata. Exclamation mark signs and black dots (Dermlite photo^®).

Figure 4 Telogen effluvium. Short regrowing hair (videodermoscopy, 70 x magnification). Photo courtesy of Prof. Lidia Rudnicka.

Figure 5 Trichotillomania. Hairs broken at differents lengths, with trichoptilosis (split end) and black dots (videodermoscopy, 70 × magnification). Photo courtesy of Prof. Lidia Rudnicka.

Figure 6 Lichen planopilaris. Intense perifollicular scaling and tubular structures (Dermlite Photo^®).

Figure 7 Frontal fibrosing alopecia. Absence of follicular openings, predominance of follicular units with only 1 hair, mild perifollicular scaling and perifollicular erythema (Dermlite photo^®).

Figure 8 Discoid lupus erythematosus. Characteristic large yellow dots and arborizing vessels (videodermoscopy, 70 x magnification). Photo courtesy of Prof. Lidia Rudnicka.

Figure 9 Diagnostic algorithm for trichoscopic findings of hair loss diseases. From Inui S. Expert Rev Dermatol 2012: 7.