Dermaimaging

In a 46-year-old woman, on the dorsa of hand

What to see at dermoscopy:

-raised and hyperqueratotic border (arrow)
-central light brown pigmentation                                                                                                                                                                                                                                  Dermoscopy in favor of porokeratosis

Comments: the dermoscopic findings are present even in early lesions; the hiperqueratotic border corresponds to the histological cornoid lamella

In a 53-year-old woman, multiple lesions on the sole. 

What to see at dermoscopy:

First picture corresponds to double hyperkeratotic papules with a central black dot (under the nail plate). At the second picture, the right lesion was gently shaved and white ovoid structures over the skin were observed which corresponds to eggs.
Dermoscopy in favor of tungiasis

Comments: There is upcoming evidence that dermoscopy facilitates the in vivo diagnosis of skin infections and infestations (viral warts, molluscum contagiosum, scabies,
 pediculosis, tinea nigra, tungiasis, cutaneous larva migrans). For more information read: Cabrera R. et al, Br J Dermatol, 2009. 160: 1136-1137

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

In a 44-year-old woman, on the forearm

What to see at dermoscopy:

-whitish structureless areas, showing projections of varying sizes, from thin spikes (comb-like appearence) to broad arboriform ramifications
-linear vessels
Biopsy was indicated.
Histopathological correlation: active lichen planus

Comments: sometimes blue-gray dots (corresponding to dermal melanophages) are also observed.
For more information: Vazquez-Lopez F, Gomez-Diez S, Sanchez J, Perez-Oliva, N. Dermoscopy of active Lichen Planus. Arch Dermatol 143, 2007:1092-1093