Dermaimaging

In a 35-year-old man, on the scalp

What to see at dermoscopy

-hair diameter diversity
-brown halo at the follicular ostium around the emergent hair shaft
-focal atrichia (empty follicles)
Dermoscopy in favor of androgenetic alopecia

Comments: androgenetic alopecia (AGA) is the most common form of hair loss (80 and 50% of men and women, respectively). Hair thinning is limited to the frontal, temporal, and vertex areas (androgen-dependent scalp regions) and dermoscopy is usefull to detect early AGA and for differential diagnosis with telogen effluvium.

In a 45-year-old woman, on the scalp

What to see at dermoscopy:

-loss of follicular openings
-follicular pluggings
-incontinentia pigmenti
-erythema
-arborizing vessels
-telangectasia
-peripilar casts
Biopsy was indicated
Histopathology correlation: discoid lupus erythematosus

Comments: the differential diagnosis of this lesion includes lichen planopilaris.
For more information: Ross et al.. Videodermoscopy in the evaluation of hair and scalp disorders. 2006. J Am Acad Dermatol 55: 799-806