Dermoscopic examination of the nail bed and matrix

Abstract Background Dermoscopy has furthered advances in the differential diagnosis of longitudinal melanonychia; however, fewer details observed in the nail, as compared to skin lesions, make interpretation difficult. Methods Ten cases of longitudinal melancholia, from several etiologies, were submitted to direct dermoscopic examination of the nail bed and matrix. Results We observed the presence of globules, streaks, and pigment network in the nail bed and matrix, which are dermoscopic features not seen in the nail plate. Conclusions This procedure enables visualization of dermascopic features not seen in the nail plate, making the diagnosis of melanocytic lesions easier.     

Azidothymidine-induced nail pigmentation

A patient with acquired immunodeficiency syndrome (AIDS) showed longitudinal brownish-gray bands on several fingernails and toenails four months after starting therapy with azidothymidine. Nail changes during azidothymidine therapy and AIDS-related nail changes are discussed briefly.     

常见甲病的皮肤镜表现

【摘要】 指（趾）甲类疾病病因多样,临床表现类似。皮肤镜为无创检查,可通过观察甲小皮、甲皱襞、甲板等部位,快速、全面地观察早期病甲的变化,可用于甲病的诊断及治疗或手术效果评价。本文结合2017年6月至2019年2月中南大学湘雅医院皮肤科明确诊断的指（趾）甲类疾病的皮肤镜表现,总结常见甲病的皮肤镜表现,以期提高临床医师对甲病的认识。     

甲单位肿瘤皮肤镜表现

正1 甲单位良性肿瘤及肿瘤样表现1.1 甲乳头状瘤(Onychopalilloma)甲乳头状瘤是来源于甲床和甲母质远端部分的良性肿瘤[1],甲乳头状瘤表现多样,无明显特异性,最常见的临床特征为纵行红甲,也可表现为纵行白甲、黑甲、裂隙状出血、远端甲下局灶性角化性团块、远端甲分离伴或不伴甲裂隙等(图1a)。皮肤镜表现:起源于甲半月均质的纵行条带(红色、白色、黑色),伴条带内有碎裂出血,甲远端游离缘可见V性凹口,其下方可见角化性团块     

甲真菌病和甲银屑病的皮肤镜特征分析

【摘要】 目的 分析甲真菌病和甲银屑病的皮肤镜特征。方法 2017年3月至2018年3月在湖北襄阳市中心医院皮肤科收集就诊的甲真菌病和甲银屑病患者各128例,对病甲皮肤镜图像进行比较。计数资料比较采用χ2检验和Fisher精确检验分析。结果 甲真菌病出现7种皮肤镜模式,分别为锯齿状边缘69例（53.91%）、纵行条纹72例（56.25%）、锥形甲角化30例（23.44%）、甲板增厚21例（16.41%）、甲黑点5例（3.91%）、甲剥离26例（20.31%）和甲变色23例（17.97%）。其中,锯齿状边缘和纵行条纹在远端侧位甲下型甲真菌病中出现的频率明显高于其他3种亚型,差异有统计学意义（均P＜0.001）,锥形甲角化在全甲毁损型甲真菌病中出现的频率明显高于其他3种亚型,差异有统计学意义（χ2 = 42.020,P＜0.001）,甲板增厚、甲黑点、甲剥离和甲变色在4种甲真菌病临床亚型中的分布差异无统计学意义（均P＞0.05）。甲银屑病出现7种皮肤镜模式,分别为点蚀征61例（47.66%）、油滴征41例（32.03%）、裂片形出血41例（32.03%）、甲床毛细血管扩张23例（17.97%）、甲板增厚20例（15.63%）、甲剥离20例（15.63%）和甲变色13例（10.16%）,其中油滴征在寻常性和关节病性银屑病中出现的频率明显高于其他两种亚型（P = 0.019）,甲床毛细血管扩张在脓疱性银屑病中出现的频率明显高于其他3种亚型（P = 0.047）,点蚀征、裂片形出血、甲板增厚、甲剥离和甲变色在4种银屑病临床亚型中的分布差异无统计学意义（均P＞0.05）。结论 甲真菌病皮肤镜下特征包括锯齿状边缘、纵行条纹、锥形甲角化和甲黑点,银屑病甲皮肤镜下特征包括点蚀征、油滴征、裂片形出血和甲床毛细血管扩张,二者同时出现的镜下表现包括甲板增厚、甲剥离和甲变色。     

Cyclophosphamide induced nail pigmentation

Cyclophosphamide therapy may occasionally cause black pigmentation of the nails. We report five cases with this side effect and review the data on eleven cases in the literature. These changes start in the proximal nail beds and progress distally; on withdrawal of cyclophosphamide, clearing of the nail pigmentation proceeds in a similar fashion. The development of the nail pigmentation does not bear any relation to the primary condition for which cyclophosphamide was prescribed. The dose of the drug before the onset of pigmentation ranged from 1.2 to 12.3 g; the duration of treatment ranged from 10 days to 26 weeks. The mechanism of the nail pigmentation is unknown.     

Diagnosis and therapy of streaked nail pigmentation

Melanonychia striata longitudinalis is due to a focal increase in number and/or activity of melanocytes in the nail matrix, resulting in the continuous production of large amounts of melanin which are transferred to the nail cells and grow out with the nail plate. Histologically, either benign melanocytic hyperplasia, lentigo simplex, nevocellular nevus, atypical melanocytic hyperplasia or acral lentiginous melanoma may be found. Longitudinal pigmented streaks in the nails of Caucasians tend to be malignant rather than benign. Thus a biopsy for proper histological diagnosis is strongly advised. Melanonychia striata may also occur as a symptom of rare syndromes and diseases or be due to therapy. Differentiating this condition from subungual hematoma and infections with chromogenic bacteria and fungi may be difficult.     

Peculiar pattern of nail pigmentation following cyclophosphamide therapy

Cyclophosphamide is one of several cancer chemotherapy agents that can cause nail hyperpigmentation. We report a patient who began to have an unusual form of nail pigmentation after 8 months of receiving monthly pulses of dexamethasone-cyclophosphamide. The patient developed nail pigmentation that started proximally and spread distally but involved only the nails of the thumb, index finger, and half the middle finger of both hands.     

Dermoscopic detection of nail fold capillary abnormality in patients with systemic sclerosis

The diagnosis of systemic sclerosis (SSc) is often difficult. The purpose of the present study was to find the distribution of nail fold capillary abnormality in SSc. Sixty-two patients with SSc (male : female = 7:55, age 21-86 years, mean 60.1) admitted to the outpatient clinics were studied. Eighteen age- and sex-matched normal subjects, 28 patients with systemic lupus erythematosus (SLE) and 10 with dermatomyositis (DM) were also studied. Nail fold capillary loops were observed under immersion oil at a magnification of ×40 with a light microscope. Dilated capillaries, nail fold bleeding and avascular areas were found by dermoscopic observation. The distribution of dilated capillaries, nail fold bleeding and avascular areas in normal controls showed in one (5.6%), one (5.6%) and four cases (22.2%), respectively. The distribution of dilated capillaries, nail fold bleeding and avascular area in SSc patients showed in 27 cases (43.5%), eight cases (12.9%) and 16 cases (25.8%), respectively. The distribution of dilated capillaries and/or nail fold bleeding in SSc patients (29/62, 46.8%) was significantly elevated than that of normal controls (2/18, 11.1%) (P < 0.01). The distribution of overall abnormality in SSc (30/62, 48.4%) showed no significant difference compared with that of normal controls (4/18, 22.2%). Sensitivity and specificity for dilated capillaries and/or nail fold bleeding and overall nail fold abnormality in SSc patients compared with normal controls was calculated as 40.8% and 93.5%, 34.8% and 88.2%, respectively. Dermoscopic observation of dilated capillaries and/or nail fold bleeding is a sensitive and specific method for the detection of SSc.     

An approach to initial examination of the nail

A systematic method of examining nail disorders is important. A patient questionnaire (sample provided) and a basic method of categorizing various problems are helpful tools. Thorough investigation usually yields a diagnosis.