Dermoscopy in the Evaluation of Nail Disorders

Abstract

Nail dermoscopy was initially used only in the assessment of nail pigmentation, but now it is widely utilized for the evaluation of many nail disorders. In daily practice, dermoscopy may confirm clinical diagnoses and guides in the management of nail diseases and treatments, permitting a better visualization of symptoms. Dry dermoscopy is required for evaluation of the nail plate surface, while gel as an interface is necessary for assessment of nail pigmentation and onycholysis, as well as for the evaluation of the distal nail margin. In this review, we describe the dermoscopic features of the most important nail disorders, looking at the different areas of the nail. Dermatoscopic changes that usually accompany specific nail diseases are also reviewed.

Keywords: Capillary alterations; Dermoscopy; Hyponychium; Melanonychia; Nail tumor; Onycholysis; Onychoscopy; Splinter hemorrhages; Subungual hyperkeratosis.

Fig. 1

Capillaroscopy in dermatomyositis: giant capillaries with arborescent appearance and microhemorrhages. Magnification, ×50.

Fig. 2

Capillaroscopy in systemic lupus erythematosus: tortuous, oddly shaped loops with serpiginous appearance. Magnification, ×20.

Fig. 3

Dermoscopy of pyogenic granuloma: reddish mass with irregular vessels and white central area. Magnification, ×10.

Fig. 4

Dry dermoscopy of periungual warts: hyperkeratotic and rough lesion with small black dots. Magnification, ×10.

Fig. 5

Dry dermoscopy easily enhances visualization of the longitudinal fissures of the nail plate due to lichen planus with partial anonychia and dorsal pterygium. Magnification, ×10.

Fig. 6

Dry dermoscopy enhances visualization of the typical surface nail plate alterations with recent trachyonychia in the proximal nail plate. Magnification, ×10.

Fig. 7

Dry dermoscopy of nail psoriasis with irregular pitting. Magnification, ×20.

Fig. 8

Lamellar onychoschizia of a fingernail: the distal portion of the nail plate peels off in layers, and horizontal and vertical breakages are easily visible with dry dermoscopy. Magnification, ×20.

Fig. 9

Dry dermoscopy shows thin fissures on the nail plate and opaqueness of the white spots of nail fragility due to superficial degranulation of the nail plate from chemicals. Magnification, ×20.

Fig. 10

Dermoscopy with gel shows white bands within the nail plate in transverse leukonychia of the right toenail. Magnification, ×20.

Fig. 11

The white area in the lunula of a proximal subungual onychomycosis is well visible by dermoscopy. Magnification, ×20.

Fig. 12

Dermoscopy shows a nail plate with several small white, opaque, and friable patches in white superficial onychomycosis. Magnification, ×20.

Fig. 13

Dermoscopy shows a bright green color that fades to yellow in case of onycholysis. Note the border of the subungual pigmentation, where the color typically fades into pale green at the margin of detachment. Magnification, ×10.

Fig. 14

Dermoscopy of onychopapilloma presenting as a longitudinal red band associated with splinter hemorrhages. Magnification, ×10.

Fig. 15

Dermoscopy of a glomus tumor with a deep red-purple subungual mass. Magnification, ×20.

Fig. 16

Dry dermoscopy of the third fingernail of a left hand with alternance of multiple and parallel red and white bands in Darier disease. Magnification, ×10.

Fig. 17

Dermoscopic aspect of distal subungual onycholysis, which is yellow-whitish in color due to the colony's formation and corresponds to a pattern of longitudinal striae. Magnification, ×10.

Fig. 18

Dermoscopy of dermatophytoma: subungual accumulation of dermatophytes and scales, presenting as a round yellow-orange subungual area, connected by a thin band to the distal edge of the nail plate. Magnification, ×10.

Fig. 19

Dermoscopy of a recent hematoma (a), presenting as a red-to-black discoloration of the fingernail and proximal fading of the red color, and of a late stage of the same subungual hematoma (b), presenting with a darker color. Magnification, ×10.

Fig. 20

a Clinical picture of multiple nails affected by melanonychia due to drugs. b Dermoscopy of melanocytic activation, with a gray background of the band and thin grayish regular and parallel lines. b Magnification, ×20.

Fig. 21

Dermoscopic pattern of a nevus in a 3-year-old child with the presence of a brown background with longitudinal brown-to-black irregular and parallel lines with irregular spacing and thickness. Magnification, ×20.

Fig. 22

High magnification of the dermoscopic features of nail melanoma, with a brown-to-black background of the band and longitudinal lines irregular in thickness, spacing, color, and parallelism. Magnification, ×20.

Fig. 23

Dermoscopy of fungal melanonychia with yellow streaks associated with homogeneous pigmentation and brown-black discoloration with irregular accumulation of black pigment and scales under the nail plate. Magnification, ×10.

Fig. 24

Dermoscopy of the linear and regular margin of an onycholytic area due to traumatic onycholysis. Magnification, ×10.

Fig. 25

Dermoscopy of nail psoriasis with onycholysis presenting a slightly dented margin of the onycholytic area surrounded by a yellow-orange band and splinter hemorrhages and irregular pitting. Magnification, ×10.

Fig. 26

Typical dermoscopic aspect of onychomatricoma in the frontal view, with a honeycomb pattern. Magnification, ×10.

Fig. 27

Dermoscopy of periungual tissue with the micro-Hutchinson sign and longitudinal lines irregular in thickness, spacing, color, and parallelism in a melanoma. Magnification, ×20.