The Imaging Research Of Psoriatic Nails And Nailfold Capillaries

Background: The prevalence of nail psoriasis(NP)among patients with psoriasis is up to 50%.The appearance of psoriatic nails may cause psychological distress of the patients.And a considerable number of patients suffer from social obstacles and functional impairments which make their quality of life from bad to worse.Currently,reports on dermoscopic features and changes of the nailfold capillaries of NP are not conclusive.Dermoscopy and digital video nailfold capillaroscopy are efficient and noninvasive,which can be widely used in changes of nails and nailfold capillaries.Objective: The aim of this study was to investigate specific dermoscopic features of fingernail psoriasis and the correlation to the severity of nail lesions or systemic inflammation,the correlation between psoriasis severity of skin and nail,the severity difference between fingers,and changes of nailfold capillaries in patients with psoriasis.Methods:1.Dermoscopy of NP: this study recruited patients with fingernail psoriasis or onychomycosis.In all cases,the involved fingernails were examined by a handheld dermatoscope.Images of involved fingernails were recorded by a mobilephone.A detailed history were recorded,and NAPSI,PASI,BSA were evaluated.2.Digital video nailfold capillaroscopy of NP: this study recruited psoriatic patients with or without nail involved and healthy volunteers.The fourth finger of the non-dominant hand of all individuals were examined by a nailfold capillaroscopy.Images were recorded and analyzed.SPSS and Graphpad were used for statistical analysis and the significance threshold was p < 0.05.Results:1.Dermoscopy of NP: this observational study recruited 135 patients with fingernail psoriasis(1186 fingernails)and 30 patients with onychomycosis(80 fingernails).We identified onycholysis was the most common feature(93.3%)of fingernail psoriasis.Red lunula,longitudinal fissures,transverse grooves,nail plate crumbling,trachyonychia,oil-dropping sign,erythematous border of an onycholytic area,subungual hyperkeratosis,and dilated streaky capillaries were relevant to NP severity(P<0.05).Red lunula,transverse grooves,nail plate crumbling,trachyonychia,oil-dropping sign,erythematous border of an onycholytic area,splinter hemorrhages and dilated streaky capillaries were relevant to systemic inflammation severity(P<0.05).The NP severity was positively associated with skin lesion severity and involved body surface area(P<0.0001 or P<0.0001).The severity of thumb was severer than the other fingers(P<0.05).2.Digital video nailfold capillaroscopy of NP: psoriatic patients had significant nailfold capillary abnormalities,including decreased capillary density(P<0.001),dilated capillary loops(P<0.05),decreased blood flow velocity,and increased proportion of abnormal morphological capillaries.Among psoriatic patients,there was no significant difference in the density or capillary architecture between those with and without NP,but the blood flow velocity of psoriatic patients with NP was significantly lower than in those without NP(P<0.05).In total 63% of patient with NP had over 30% abnormal morphological capillaries.Conclusion:Dermoscopy and digital video nailfold capillaroscopy can provide powerful clues to the diagnosis and severity evaluation of NP.