Immunohistochemical study of specialized nail mesenchyme containing onychofibroblasts in transverse sections of the nail unit

In the frozen longitudinal section of the nail unit, CD10 was previously found in nail mesenchymal cells beneath nail matrix, and we proposed calling the nail mesenchymal cells onychofibroblasts. In this study, to further characterize nail mesenchyme containing onychofibroblasts, we examined the expression of several mesenchymal markers immunohistochemically in transverse paraffin sections of the nail unit. CD10 was strongly expressed in the nail mesenchyme containing onychofibroblasts beneath the nail matrix. However, CD10 was not observed in dermal fibroblasts and surrounding extracellular matrix of the lateral nail fold (LNF), except around blood vessels and eccrine structures. In addition, versican was expressed diffusely in the nail mesenchyme containing onychofibroblasts in contrast to the dermis of LNF. Fibrillin, which is a major component of elastic fiber in the dermis, was expressed very weakly on the nail mesenchyme below the nail matrix but was expressed strongly in the dermis of LNF. These findings support the existence of specialized nail mesenchyme containing onychofibroblasts that is distinguished from the dermis of LNF.     

获得性非真菌性甲病的临床与病理特征分析

目的 通过甲单位病理确诊不明原因的获得性非真菌性甲病,探讨不同甲病与甲损害类型间有无关联。方法 对临床上无任何皮肤、黏膜损害,甲真菌学检查阴性的52例甲病患者,首先根据甲损害特征分类,通过纵行甲活检手术方法取材进行甲单位病理检查。然后将确诊的不同甲病与甲损害的特征相比较。结果 病理确诊甲银屑病14例,以脆甲、厚甲、点状凹陷等多见。甲扁平苔藓21例,甲损害分为两大类,第一类为甲萎缩、甲胬肉和无甲;第二类为甲纵嵴、远端甲裂和薄甲。甲非特异性湿疹样变17例,损害主要有沙纸样甲和甲纵嵴。结论 某些类型的甲板损害与甲单位病理诊断之间存在着关联性,了解这些特点对获得性非真菌性甲病的临床诊断、鉴别诊断提供参考依据。     

Identification of nail features associated with psoriasis severity

There are no detailed studies of the prevalence of nail psoriasis and clinical characteristics of psoriatic nail involvement, including nail features associated with disease severity. Therefore, we designed a study to investigate the prevalence and characteristics of psoriatic nail involvement in patients with psoriasis and determine the relationship between psoriatic nail features and severity of nail psoriasis and cutaneous psoriasis. The Nail Psoriasis Severity Index (NAPSI) was used for evaluation of the severity of nail lesions. The presence of nail fold psoriasis (NFP) was also assessed. The severity of psoriasis was evaluated by calculating the Psoriasis Area and Severity Index (PASI). As a result, the prevalence of nail psoriasis was 85.5%. Pitting was the most common clinical feature (55.6%). The severity of nail psoriasis was not affected by medical parameters, although patients with localized pustular psoriasis tended to have more severe nail psoriasis than did those with chronic plaque psoriasis. When comparing the mean NAPSI and the mean PASI according to nail lesions, we found that subungual hyperkeratosis (SH) and NFP were significantly associated with the severity of both nail psoriasis and cutaneous psoriasis. Psoriatic nail changes were most common in the first digit. Conclusively, the majority of patients with psoriasis had psoriatic nail involvement, and Koebner's response seems to be closely related to the induction of nail psoriasis. To limit progression of the disease, psoriatic patients with SH or NFP should be examined thoroughly because those clinical features reflect the levels of severity of both nail and cutaneous psoriasis.     

Bowen's disease of the nail bed

A 77-year-old man presented with a 2-year history of left thumbnail dystrophy, purulent discharge and aching pain. There was no history of trauma. On examination there was a linear area of nail dystrophy and dyschromia of the nail bed. The nail plate was thinned proximally. No other digits were affected. There was no lymphadenopathy. X-ray of the digit was normal. Longitudinal nail biopsy revealed Bowen's disease along the length of the nail bed and nail matrix specimen. After avulsion of the nail plate, the nail matrix and tumour were fully excised. The defect was repaired with a split-skin graft. His symptoms were relieved.     

Subungual Posttraumatic Ectopic Nail

Ectopic nail is defined as the malformation of nail tissue in a location other than the usual nail unit. We present a 12‐year‐old boy with a single dystrophic thumb nail after an injury. The nail was observed under the original nail and it is linked to the original nail plate by longitudinal bridge formation with parallel growth. According to these clinical findings, the diagnosis of subungual posttraumatic ectopic nail was made.     

An L-shaped flap for the correction of pincer nail deformity: A case report

Pincer nail deformity is characterised by an excessive transverse curvature of the nail plate that increases along the longitudinal axis of the nail. Although various corrective techniques have been described, there is, no consensus regarding the optimal correction method. We report a novel surgical technique for correcting pincer nail deformity in a 45-year-old male with bilateral omega-shaped pincer nail deformity of the great toes. The nail matrix on the side showing the more severe curvature was removed, and a flattened nail bed was achieved after suturing. An L-shaped skin and subcutaneous tissue flap was also created 5 mm from the junction between the side of the nail with the milder curvature and the distal nail fold. After healing, the pincer nail deformity was successfully eliminated. At the 1-year follow-up, recurrence was not observed and the appearance of toes was satisfactory. This novel surgical technique is simple, minimises damage to the surrounding tissue, avoids injuring the nail bed blood supply and has few postoperative complications.     

甲沟重建联合甲内卷矫正术治疗重度嵌甲型甲沟炎48例

目的:评价甲沟重建联合甲内卷矫正术治疗嵌甲型甲沟炎的临床疗效。方法:选择2019年12月至2021年10月在我科就诊的重度嵌甲型甲沟炎患者48例，均采用甲沟重建联合甲内卷矫正术治疗。手术要点：(1)楔形切除增生的肉芽组织缩小甲襞，通过新的缝合方法使甲襞侧组织与甲床同一水平，构建正常甲沟；(2)橡胶片固定在甲缘下以钝化甲边缘；(3)用橡皮筋牵拉甲缘下橡胶片以抬高甲侧缘以纠正甲内卷畸形。结果:48例患者(81个拇趾)全部治愈，甲形态正常且美观，随访6个月无复发。结论:甲沟重建联合甲内卷矫正术疗效好。     

Glomus tumor-induced longitudinal splitting of nail mimicking median canaliform dystrophy

Median canaliform deformity of the nail is an uncommon entity, where there is longitudinal splitting of the nail. Longitudinal splitting of the nail is a rare phenomenon and can also occur following number of growths arising in the nail matrix. On examination there was a longitudinal split in the nail plate, beginning in the distal nail fold and extending proximally all the way to the proximal nail fold. There was a small, almost indiscernible, swelling in that area, which was exquisitely tender. The split part of the nail showed a little discoloration. There was no discharge, bleeding, or subungual mass visible. 'Love test' was positive in this case. After nail avulsion, a small 2 mm x 4 mm nodule was exposed and excised. Histopathological examination of the tumor showed a mantle of glomus cells surrounding the blood vessels.     

Determinants of nail thickness and length

Summary The determinants of final nail thickness and length at its point of detachment at the onychodermal band were studied in 20 normal great toe-nails, removed after injury, by correlating measurements of nail thickness, taken at six anatomical points, with length of nail and its lunular (matrical) and ventral nail components. Final nail thickness at the onychodermal band was related to initial thickness of the proximal matrix, and independently to the lengths of the lunula and ventral nail, but not to final nail length. There was an increase in nail thickness with age, particularly in the first two decades; this appeared not to be due to a decrease in frictional loss of nail.     

In vivo measurement of water content of the fingernail and its seasonal change

BACKGROUND/AIMS: Recently, there has been increasing awareness regardless keeping nails in good condition. Maintenance of an optimum water level in the nail plate is very important since water content affects the nail condition. However, a simple method for in vivo measurement of water in the nail plate quantitatively has not been reported. In this study, we applied Near infrared spectroscopy (NIR)-based prediction of water content of the cut nail plate to in vivo measurement to obtain information about the seasonal change of water in the fingernail. METHODS: Diffused reflectance spectra of the nail plate of the fingernail were collected in the NIR region with an NIR spectrometer in vivo both in summer and winter from the same 15 Japanese female subjects. The water content of the nail plate in vivo was calculated from the NIR spectrum using partial least square regression analysis. RESULTS: It was possible to apply NIR-based prediction of water content of the cut nail plate to in vivo measurement. We also found that the water content of the nail plate varied from person to person but not with the finger of the individual. The average water content of the nail plate was significantly lower in winter than in summer (P<0.05). In summer, the water content in the double-layered nail tended to be higher than a nail in good condition (P<0.1) and significantly lower in the split nail (P<0.05). There was no significant difference between the groups in winter. On the contrary, the amount of water absorption tended to vary depending on the nail condition. A large amount of water was absorbed in the double-layered nail and a small amount in the split nail both in summer and winter. CONCLUSION: The water content of the nail plate of fingernail was predicted by in vivo measurement using NIR spectrometry. Physiological information of the nail in vivo, such as aging and other disorders could be obtained by this method.     

Einfluss eines ureahaltigen Lackes auf die Nagelqualität

BACKGROUND: Urea is a well-known humectant. The aim of our study was to evaluate the in vivo effect of 10% urea lacquer on nail quality. METHODS: 60 healthy probands with brittle nails were included in a randomized, controlled study. The nail lacquer was applied once (n=30) or twice daily (n=30) on one hand for 28 days, while the other hand served as untreated control. Assessments included clinical evaluations and bioengineering measurements. RESULTS: Application of the nail lacquer was well-tolerated and led to a significant clinical improvement of nail surface morphology, nail plate consistency, reflection of the nail plate surface, appearance of the cuticle and the nail fold. Sonographic nail density was slightly increased. No relevant changes were found in nail thickness and transonychial water loss. CONCLUSIONS: Nail lacquer containing urea improves the cosmetic appearance of fingernails.     

Ultrasound structure of the human nail plate

The structure of the normal human nail plate is described using an ultrasound scanner (20 MHz A). Postmortem studies, including examination of nail plate biopsy specimens before and after desiccation, were performed and compared with in vivo structures. Two compartments could be identified in the nail, ie, a dry and superficial compartment with the ultrasound velocity of 3103 m/s and a humid and deeper compartment with an ultrasound velocity of 2125 m/s. The ultrasound velocity of the entire nail was 2459 m/s, and the water content was 35% wt/wt. Underneath the nail, echoes from the nail bed were seen. Ultrasound was concluded useful for noninvasive measurement of nail thickness and examination of internal nail structure.     

部分甲基质切除甲沟重建治疗嵌甲

目的研究1种利用甲侧襞皮瓣改变甲体与甲沟的位置结构,从而彻底治愈嵌甲的手术方法。方法切除部分甲体、甲床,并利用甲侧襞皮瓣重建甲床、甲沟、甲侧襞联合结构。结果2000年1月～2003年5月对158 例嵌甲患者,足趾209、手指3,共276侧嵌甲进行甲沟重建手术。随访6月～2年,效果满意。结论该手术从根本上治愈嵌甲,且并发症少,复发率极低。     

Evaluation of nail involvement in patients with chronic cutaneous graft versus host disease: a single-center study from Turkey

Although graft versus host disease (GVHD) is associated with a myriad of cutaneous signs, nail involvement is rarely mentioned in the literature. This study was conducted at the Department of Dermatology and The Bone Marrow Transplantation Unit of Hematology. All patients were examined clinically for presence of nail abnormalities. Severity of nail involvement was assessed as mild or severe. Of 28 patients diagnosed with chronic cutaneous GVHD, 14 had nail manifestations. Longitudinal ridging was the most frequently observed nail change on both the fingernails and the toenails. Severe nail changes such as ptergyium and onicoatrophy were noted in a few patients. As a result we could not find any relationship between nail changes and clinical severity but there was a relationship between nail changes and duration of disease. Nail manifestations could be responsible for considerable morbidity.     

Quantification of regional matrix nail production

The relative nail producing capacity of different regions within the nail matrix has not been quantified. In order to do this, the number of nail plate cells in the dorsoventral axis of 12 human great toenails was counted at five sites in the longitudinal axis, and compared with direct measurements of nail plate thickness at the same sites. The mean number of nail cells in the nail plate reached a maximum at the lunula, wilh no further increase along the length of the nail bed. At the mid-point between the proximal tip of the germinal matrix and lunula, mean cell numbers achieved 81 % of the value at the lunula. Mean nail thickness was only 90% of its maximum at the lunula. with a further significant increase (P=0.02) between the lunula and end of the nail bed. These observations suggest that the proximal nail matrix is the main source of nail within the matrix. This is consistent with clinical experience where distal matrix surgery has a low potential for scarring in comparison with proximal matrix surgery. The additional finding of increased nail thickness, but not cell numbers, along the nail bed make it likely that cells within the nail plate change shape as they move distally.     

Continuous formation of nail along the bed

To resolve the problem of whether nail is formed continuously along the length of the nail bed as well as by the germinal matrix, nail thickness was measured at six anatomical points along the length of 20 normal big toe-nails removed after injury. Nail water content was constant at 9–10% along the nail length, and the nails did not shrink with dehydration. Approximately 79% of nail thickness was contributed by the nail matrix, and 21% by the nail bed. The rate of nail production was constant at 0.13 mm/mm along the lunula and 0-027 mm/mm along the whole bed from the distal lunula to the point of separation at the onychodermal band: the fractional cbange in linear growth and thickness showed less variation than absolute change. The continuous production of nail by the bed provides a simple biological solution to the problem of attachment of a continuously moving plate. It provides a source of entry of drugs into the distal nail piate, and a rationale for the use of much shorter courses of antifungai drugs than previously believed possible.     

A case of congenital onychoheterotopia on both fifth fingers

The present report illustrates the extremely rare clinical features of congenital onychoheterotopia (ectopic nail). The amino-acid composition of congenital ectopic nail was estimated, and the surface of nail clippings was compared to the patient's normal nail using scanning electron microscopy.     

Severe Nail Fold Psoriasis Extending from Nail Psoriasis Resolved with Ustekinumab: Suggestion of a Cytokine Overflow Theory in the Nail Unit

Because nail psoriasis is difficult to treat, therapy with many biological drugs has been attempted. Ustekinumab is approved for chronic plaque psoriasis and psoriatic arthritis (PsA), with some trials reporting nail improvement using this agent. A 51-year-old man with severe chronic plaque psoriasis had severe involvement of all fingernails and toenails, with accompanying nail fold psoriasis. He also had PsA of the small joints of the fingers. Despite multiple conventional therapies, the nail lesions did not improve, and his nail psoriasis severity index score was 97. After a fourth ustekinumab injection, most of the fingernail psoriasis was resolved, and only hyperkeratosis remained on both large toenails. Because the nail plate, nail fold, and small joints of the fingers are closely apposed structures within a small area, cytokines produced from the nail units overflow to the nail fold and small joints and can induce nail fold psoriasis and PsA.     

Ultrasonography reveals nail thickening in patients with chronic plaque psoriasis

Nail psoriasis is usually investigated and diagnosed by clinical examination. Ultrasonography is a non-invasive imaging technique for studying soft tissue involvement. The objective of this study was to estimate nail involvement in patients with chronic plaque psoriasis by ultrasonography. Prevalence, clinical type and severity of nail involvement according to nail psoriasis and severity index (NAPSI) were investigated in 138 patients with psoriasis. The thickness of the plate and bed of the fingernails was measured in 54 patients with psoriasis, 46 healthy controls and 37 patients with chronic eczema, using an ultrasonographic system equipped with a frequency transducer of 18?MHz. The prevalence of nail psoriasis was 73?% (102 out of 138). Onycholysis and thickening of the nail plate were the most common clinical type affecting 56 and 50?% of patients, respectively; splinter haemorrhages was the less common involving 10?% of patients. The mean NAPSI score was 18.4?±?17.5 (SD; range 0–107). The thickness of fingernail plate and bed was significantly higher in patients with psoriasis with nail disease compared to healthy controls and patients with chronic eczema (p?<?0.001). There was a linear correlation between NAPSI and plate and bed nail thickness (r?=?0.52 and r?=?0.38, p?=?0.001). Increased nail plate and bed thickness was observed also in patients with psoriasis without clinically apparent nail involvement. In conclusion, thickening of the nail is a common feature of nail psoriasis also in patients without clinically apparent nail involvement.