Dermoscopy to detect signs of subclinical nail involvement in chronic plaque psoriasis: A study of 68 patients

Abstract

Background:Onychopathies constitute one of the major challenges faced by a dermatologist in terms of its early detection and diagnosis. Utility of dermoscope as a tool for detection is increasing by the day and its use in onychopathies needs to be explored.Aims:To study the dermoscopic features of nails in patients of chronic plaque psoriasis.Materials and Methods:In a cross-sectional study, a total of 68 patients with chronic plaque psoriasis were recruited. Dermoscopy of nail plate was conducted and were compared with equal number of age and sex matched healthy volunteers.Results:Forty-six patients showed dermoscopic findings. Twenty-two patients did not show any dermoscopic findings. Coarse pits (18/46, P < 0.0001), onycholysis (10/46, P < 0.001), oil drop sign (2/46, P = 0.12) and splinter hemorrhages (5/46, P = 0.05) were seen. In addition certain findings of interest were stout, globose, dilated, pink- to red-colored nail bed vessels arranged longitudinally at the onychodermal band surrounded by a prominent halo (9/46, P = 0.01). In contrast, splinter hemorrhages appeared as streaks and were purple in color.Conclusion:In a psoriasis patient, dermoscope can be a useful tool to detect early nail involvement in psoriasis and aid in differentiating it from other disorders of nails.

A study of dermoscopic features of nail psoriasis

“…Salmon patches, also known as the oil drop sign, refer to the yellowish-red discolorations that appear as irregular translucent areas visible on the nail plate. As per our observations, psoriatic onycholysis has a distinctive dermoscopic appearance comprising a typical erythematous border encircling a white onycholytic area ( Figure 1 ) [ 3 – 5 , 10 – 12 ].…”

“…Whereas parakeratotic lesions within the nail bed lead to salmon patches, parakeratotic cell shedding at the level of the hyponychium leads to onycholysis. These pits, which are filled with gel and surrounded by a peripheral whitish halo, are generally easily recognized via dermoscopy [ 3 – 5 , 9 – 12 ]. On the other hand, some of the pits tend to have a more leukonychic appearance ( Figure 5 ), wherein only the intermediate and ventral matrices are affected [ 9 ].…”

“…To the best of our knowledge, very few studies have evaluated the dermoscopic features of nail psoriasis [ 12 , 15 , 16 ]. Recently, Tulika et al .…”

“…In addition, Iorizzo et al . conducted a videodermoscopic evaluation of the hyponychium in patients with psoriasis to introduce a method for visualizing the capillary network of the nails [ 12 ]. These authors aimed to assess the diagnostic value of videodermoscopy for nail psoriasis.…”

Use of filters in dermatoscopy to capture better images

“…[ 3 ] Dermatoscope is a useful tool to detect early nail involvement in psoriasis showing dilated vessel with a prominent halo, streaky capillaries, splinter hemorrhages, linear onycholysis, and oil-drop sign. [ 4 ] The vascular nail bed findings can be obscured by high back reflection of the translucent nail plate even with contact fluid and polarized light dermatoscopes. This back reflection can be overcome by using FLD filters (Opteka TM, USA) [ Figure 2 ].…”