Daniel Asz Sigall, MD MEXICO
Scalp dermoscopy 1) Hair shaft diameter heterogeneity 2) Short regrowing hairs 3) Single- hair pilosebaceous units 4) Yellow dots 5) peripilar sign 6) Honeycomb pigmentation 7) Focal Atrichia Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012
1) Hair sha3 diameter heterogeneity Typical feature of AGA > 20% in the fronto- parietal area Corresponds to hair folicle miniaturization Different of occipital area (higher hair density and less variability)
2) Short regrowing hairs Sign of severe miniaturization è Thin < 0.03mm >10% or 6 thin regrowing hairs in frontal scalp at 20x magnification: early FAGA
2) Short regrowing hairs Normal thickness>0.03 mm Thin < 0.03mm Normal Scalp (10%) Telogen effluvium Alopecia areata (regrowing patches) Androgenetic alopecia Chronic alopecia areata
3) Single- hair pilosebaceous units Normal scalp 2-4 hairs emerge for one follicular opening < 30% 1 single hair Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012
3) Single- hair pilosebaceous units Normal Scalp (2-4 hairs) AGA ( 1 hair) è è Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012
4) Yellow dots Dilated infundibular ostia filled with sebum and degenerated keratin Sign of severe miniaturization (severe cases) Irregular distribution and high variability in size and shape Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012
4) Yellow dots Alopecia areata (typical) Alopecia areata incognito Trichotillomania Chemotherapy alopecia
Brown depressed halos 1 mm around follicular ostium 5) Peripilar sign Specific and characteristic of AGA (early cases) Pathogenesis unknown: Inflamation of superficial perifollicular dermis
6) Honeycomb pigmenta@on Its a non- specific sign Frequently found in severe forms Excessive exposure to the sun
7) Focal atrichia Postmenopausal women Small bald areas Empty follicles Short vellus hairs
Rakowska et al. Major and minor dermoscopic criteria of FAGA diagnosis Major: 1) > 4 Yellow dots in frontal area 2) < Hair thickness frontal/ occipital area 3) > 10% thin hairs (< 0.03mm) frontal area Minor: 1) > Frontal/occipital ratio of single- hair pilosebaceous units 2) # Vellus hairs 3) % Perifollicular discoloration Int J Trichology. 2009 Jul;1(2):123-30.
Rakowska et al. Major and minor dermoscopic criteria of FAGA diagnosis Two major criteria or One major plus two minor criteria Diagnosis AGA with 98% specificity The presence of more than 10% thin hairs in the frontal area is by itself highly suggestive for the diagnosis Int J Trichology. 2009 Jul;1(2):123-30.
Telogen effluvium Fibrosing alopecia in pattern distribution Diffuse alopecia areata Alopecia areata incognita ê HISTOPATHOLOGY Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012
Conclusions 1) Hair shaft diameter heterogeneity (>20%) 2) Thin short regrowing hairs (< 0.03mm) 3) Single- hair pilosebaceous units 4) peripilar sign (Brown halo in early cases) 5) Yellow dots (severe cases) 6) Honeycomb pigmentation (severe cases) 7) Focal Atrichia (postmenopausal women) Rudnicka L, et al. Altas of Trichoscopy.1th edition 2012