Morphologic study of normal, ingrown, and pincer nails

Reconstruction of a nail bed with double-layer artificial dermis for a pincer nail: A case report and literature review

Background

A pincer nail (PN) is a type of nail deformity. Although it is a minor ailment, it can cause intractable pain, affecting daily work and life. Currently, there is no standard invention for PN. The main purpose of treatment is to correct the curvature of the nail, so we apply double-layer artificial dermis (DLAD), a novel treatment, for PN according to this aim.

Case presentation

A 40-year-old man suffering from PN was treated with DLAD. After 1 year of follow-up, the patient's great toenail plate of the right foot was completely grown out. His pain was relieved, and the curvature of the toenail was corrected.

Conclusion

The innovative method of using DLAD to fill the ingrown nail bed not only solves the problem of recurrent pincer nail deformity but also restores the original appearance of the toenail. It suggested that this simple procedure can be widely applied in clinical practice.

Prevalence of Onychomycosis among Patients with Transverse Overcurvature of the Nail: Results of a Cross-Sectional Study

Introduction

Transverse overcurvature of the nail (TON) represents one of the main reasons for dermatological consultations due to nail conditions. Association between TON and subungual hyperkeratosis is common and simulates onychomycosis, constituting a difficult differential diagnosis by clinical features. Many cases are treated in daily practice with antifungal therapy even without mycological confirmation. The aim of this study was to determine the prevalence of onychomycosis among patients with TON associated with subungual hyperkeratosis.

Methods

All subjects with clinical diagnosis of TON and subungual hyperkeratosis were subjected to a thorough clinical history, detailed clinical examination, digital photography, and collection of nail clipping and subungual debris for histopathological and microbiological examination (direct microscopy).

Results

Sixty-five samples were collected from 62 female (95.4%) and 3 male (4.6%) participants. Age range was between 34 and 83 years (mean age, 61.2 years). Twenty-eight samples were positive for onychomycosis, giving a 43.07% prevalence rate of onychomycosis among TON associated with hyperkeratosis.

Discussion/Conclusion

According to our data, the prevalence of onychomycosis in patients with TON associated with subungual hyperkeratosis was 43.07%, confirming the need to rule out fungal infection in TON associated with subungual hyperkeratosis prior to considering any unnecessary antifungal treatment.

Pincer Nail Deformity: Clinical Characteristics, Causes, and Managements

A pincer nail is a common nail deformity of toenails and is characterized by nail thickening and nail plate deformation. It often causes severe pain for patients. We perform a thorough literature review and an additional review of pertinent clinical cases, aiming to provide a comprehensive review of the etiology, pathogenesis, clinical classification, differential diagnosis, and treatment of pincer nail deformity (PND). Understanding the clinical characteristics and treatment progress of a pincer nail will provide clinicians with comprehensive and evidence-based information about PND, thus allowing the selection of an appropriate treatment according to the patient's request and the clinical manifestations of PND, which should maximize patient satisfaction.

Significance of Surgery to Correct Anatomical Alterations in Pincer Nails

Background

Pincer nail deformity and its causes can pose a therapeutic challenge. Ill-fitting shoes and subungual exostosis of the toes may be attributed to pincer nail formation. However, in some cases, the causes of pincer nail deformity could not be determined. The role of mechanobiology in nail configuration and deformities has rarely been considered.

Objective

The present study investigated the effectiveness of surgical procedures to correct pincer nail deformity, in terms of anatomical changes measured by radiographs.

Methods

Two surgical procedures, nail bed widening with matrixectomy or a dermal graft, were used on 30 nails in 20 patients with pincer deformity. Changes in the width, height, and curvature indices were assessed. Radiographs were obtained to evaluate the presence of osteophytes and measure the interphalangeal angle in terms of mechanobiology in nail configuration.

Results

Preoperative and postoperative assessment results revealed marked improvement objectively and subjectively. The mean width index was greater after surgery than that before surgery (84.4% vs. 64.8%). Both mean height and curvature indices were smaller after surgery than before preoperative (23.0% vs. 76.7% and 1.3% vs. 2.2%, respectively).

Conclusion

Nail bed widening with matrixectomy, which corrects anatomical alterations in pincer nails, is suggested to be suitable for patients with pincer nail deformity.

Nail Plate and Bed Reconstruction for Pincer Nail Deformity

Pincer nail deformity is a severe condition in which the nail bed becomes compressed and the nail shows an overcurvature. We retrospectively analyzed 13 pincer nail deformities treated using our nail plate and bed reconstruction technique. Visual analogue scale scores, the width of nail root, width of nail tip, height of nail tip, width index, and height index were assessed before and after surgery. The overcurvature was corrected after detachment of the nail plate. The nail fold was pushed underneath the nail plate and then fixed. The width of nail tip significantly increased after surgery (p < 0.05) and was maintained during follow-up. The height of nail tip decreased after surgery (p < 0.05). This nail plate and bed reconstruction technique is a simple and quick surgical method for correcting deformities and reduces risks of complications such as skin necrosis and infection compared to other existing surgical techniques. We recommend this efficient surgical technique for the treatment of pincer nails.

Subungual Exostosis Systematic Review and Meta-Analysis

BACKGROUND

The coexistence of deformity of the nail bed and subungual exostosis (SE) is a frequent finding in podiatric practice in the fourth and fifth decades of life. However, it has been described by other specialists as being an uncommon osteocartilaginous tumor most prevalent during the second and third decades of life. This study attempts to determine the causes of this discrepancy.

METHODS

Two authors independently conducted a systematic bibliographic review in multiple databases, podiatry sources and others, and key words were chosen to achieve a broad search strategy. Studies reporting on epidemiology and treatment of SE lesions in lower extremities in ten or more patients were selected. Initially, 197 articles were identified through database screening, with 23 meeting all inclusion and exclusion criteria. Seven articles with the ages of all of the patients were included in the analysis of age data. A comparison was then made between the diagnostic criteria for the selected 23 articles.

RESULTS

Model results reveal that, although there are some significant differences between individual studies, the main factor tested (patient's age) was clearly significant ( F_1,5.2 = 78.12, P < .001), showing that studies coming from the podiatry speciality were conducted on individuals with a mean age of 37 years higher than in studies from other specialties. Clinical and radiologic characteristics and treatment described in the podiatry literature also contrast with those in other specialties.

CONCLUSIONS

The SE described by podiatrists, in accordance with the parameters of true exostosis, is different from Dupuytren's SE and should be considered as a different pathologic entity. The authors are working on its histologic identification.

Foot loading is different in people with and without pincer nails: a case control study

Background

Recent studies suggest that pincer nails are caused by lack of upward mechanical forces on the toe pad. However, clinically significant pincer nails are also often observed among healthy walkers. It was hypothesized that in these cases, the affected toes do not receive adequate physical stimulation from walking and loading. To test this, the gait characteristics of pincer nail cases were assessed by measuring plantar pressure during walking.

Methods

In total, 12 bilateral pincer nail cases (24 affected feet) and 12 age- and sex-controlled healthy control subjects (24 ft) were enrolled in this prospective case–control study. Plantar pressure during free ambulation in both the barefoot and shod state was assessed using a digital pressure-plate system named S-Plate platform (Medicapteurs Co. France). First toe pressure and the frequencies of peak pressure in the first toe, metatarsal head, or other foot areas were calculated.

Results

In both the barefoot and shod state, the pincer nail group had significantly lower pressure on the first toe than the control group. In both the barefoot and shod state, the peak pressure area was mostly the metatarsal head area in the pincer nail group, whereas it was mostly the first toe area in the control group. Binomial logistic regression analysis revealed that peak pressure area was a significant risk factor for pincer nail development.

Conclusion

Walking behavior appears to contribute to pincer nail development. Pincer nails of walkers could be treated by correcting the walking behaviour so that more pressure is placed on the toe pad.

Correction of pincer nail deformities using a modified double Z-plasty

BACKGROUND

Pincer nail is a deformity characterized by excessive transverse curvature of the nail plate that increases distally for which many conservative and surgical corrective modalities have been recommended.

OBJECTIVE

The purpose of this study is to investigate the outcomes and safety of modified double Z-plasty in the management of symptomatic pincer nail.

MATERIALS AND METHODS

Modified double Z-plasty has been performed on 20 great toes in 12 patients from January 2008 to December 2013. The mean age of patients was 43 (range: 20-65) years. Three men and 9 women were enrolled. Visual analogue scale (VAS) score for pain, transverse angle, and width indices were investigated at the initial and the last follow-up. The average follow-up period was 2.4 years.

RESULTS

All parameters showed significant improvement after surgery. Between the initial and last follow-up, the mean VAS score fell from 7.4 to 0.3, the mean transverse angle improved from 50 to 166°, and the mean width index improved from 65.4% to 97%. In all patients, the deformity was successfully eliminated with no recurrences. No complications were identified.

CONCLUSION

Modified double Z-plasty provides a long-standing effective treatment for pincer nail deformity with an excellent esthetic result.

Anatomical characteristics and surgical treatments of pincer nail deformity

Background

Pincer nail deformity is a transverse overcurvature of the nail. This study aimed to define the anatomical characteristics of pincer nail deformity and to evaluate the surgical outcomes.

Methods

A retrospective review was conducted on 20 cases of pincer nail deformity of the great toe. Thirty subjects without pincer nail deformity or history of trauma of the feet were selected as the control group. Width and height indices were calculated, and interphalangeal angles and base widths of the distal phalanx were measured with radiography. We chose the surgical treatment methods considering perfusion-related factors such as age, diabetes mellitus, kidney disease, and peripheral vascular disease. The zigzag nail bed flap method (n=9) and the inverted T incision method (n=11) were used to repair deformities. The outcomes were evaluated 6 months after surgery.

Results

The interphalangeal angle was significantly greater in the preoperative patient group (14.0°±3.6°) than in the control group (7.9°±3.0°) (P<0.05). The postoperative width and height indices were very close to the measurements in the control group, and most patients were satisfied with the outcomes.

Conclusions

We believe that the width and height indices are useful for evaluating the deformity and outcomes of surgical treatments. We used two different surgical methods for the two patient groups with respect to the perfusion-related factors and found that the outcomes were all satisfactory. Consequently, we recommend taking into consideration the circulatory condition of the foot when deciding upon the surgical method for pincer nail deformity.

Pincer nail deformity in a patient with amyotrophic lateral sclerosis

Although several manifestations of skin involvement in cases of amyotrophic lateral sclerosis (ALS) have been reported, the pincer nail deformity has not been previously reported in a patient with ALS. The pincer nail deformity is characterized by distortion of the shape of the nail with transverse over curvature and may be associated with systemic diseases and certain medications. We herein describe the case of a patient presenting with a pincer nail deformity associated with rapidly advancing ALS. This case suggests a potential link between quickly advancing disease and the pincer nail deformity.

Clinical Evidence for the Relationship between Nail Configuration and Mechanical Forces

Summary:

Mechanobiology is an emerging field of science that focuses on the way physical forces and changes in cell or tissue mechanics contribute to development, physiology, and disease. As nails are always exposed to physical stimulation, mechanical forces may have a particularly pronounced effect on nail configuration and could be involved in the development of nail deformities. However, the role of mechanobiology in nail configuration and deformities has rarely been assessed. This review describes what is currently understood regarding the effect of mechanical force on nail configuration and deformities. On the basis of these observations, we hypothesize that nails have an automatic curvature function that allows them to adapt to the daily upward mechanical forces. Under normal conditions, the upward daily mechanical force and the automatic curvature force are well balanced. However, an imbalance between these 2 forces may cause nail deformation. For example, pincer nails may be caused by the absence of upward mechanical forces or a genetic propensity increase in the automatic curvature force, whereas koilonychias may occur when the upward mechanical force exceeds the automatic curvature force, thereby causing the nail to curve outward. This hypothesis is a new concept that could aid the development of innovative methods to prevent and treat nail deformities.

Influence of mechanical forces as a part of nail configuration

BACKGROUND

Clinicians encounter pincer nails at a high incidence among bedridden cases who are free from weight bearing. The mechanical force transmitted by walking and loading may affect the nail configuration. This study was aimed at evaluating the influence of mechanical forces on the nail configuration.

METHODS

Study 1 was conducted on a sample size of 318 great toenails, with the subjects classified into the following 3 groups: healthy volunteers, participants who were bedridden for less than 3 months, and participants who were bedridden for more than 3 months. Study 2 was conducted in 12 subjects with unilateral loading.

ASSESSMENTS

The configuration of the great toenails, in terms of the curve index (defined as the nail height/nail width), was compared.

RESULTS

In study 1, the curve index increased significantly as the duration of the bedridden state became longer (17.5 ± 4.75, 28.9 ± 11.0, 36.4 ± 9.58, respectively). In study 2, the curve index on the nonloaded side was significantly higher than that on the loaded side (40.0 ± 8.63 vs. 27.0 ± 8.39).

CONCLUSION

Our results suggest that mechanical forces may affect the nail configuration and be involved in the pathophysiology of nail deformities.

Association of hypermobility and ingrown nails

Ingrown nail (onychocryptosis) is a common condition with severe pain and various associated morbidities. Although some underlying factors are identified, its etiology remains largely unknown. Generalized joint hypermobility (GJH) is a common entity with clinical features that might prone affected individuals to ingrown nails. Herein, we investigated the incidence of GJH in patients with ingrown nails to determine possible association between hypermobility and ingrown nail formation. Patients 16-50 years of age who were undergoing treatment for ingrown nails at the dermatology clinic were consecutively enrolled into the study. Patients with known rheumatic diseases or orthopedic foot disorders were excluded. All patients were in a pain-free period at the time of examination. The control group was comprised of age- and sex-matched healthy subjects without a history of ingrown nail. Assessment of GJH was made according to Beighton criteria. Local hypermobility was evaluated by measurement of range of motion using a goniometer. Thirty-nine patients (male/female, 17/22, mean age 31.9 ± 11.3 years) and 32 healthy subjects (male/female 12/20, mean age 31.7 ± 10.4 years) were included. Patients with ingrown toe nails were more likely to have GJH compared to healthy subjects (35.9 vs. 9.4 %, p = 0.009). Toes with ingrown nails had significantly smaller maximum dorsiflexion angles (p < 0.001) compared to toes of healthy subjects. Ingrown nail formation may be associated with GJH. However, when examined locally, there is a limited range of motion in the affected toe rather than hypermobility, which could be due to the degenerative process facilitated by the hypermobility.

Correction of pincer nail deformity with phenol

From 2006 to 2009 we treated nine cases (11 toes) with pincer nail deformity of the first toe, using phenol. There were 8 women and 1 man, age range 9-81 years (mean 51). They were followed up for 7-17 months (mean 12) and all reported improvement of the pincer nail deformity and disappearance of pain from the first toes. Only one woman complained of a recurrent pincer nail deformity eight months after the first treatment, and the procedure was repeated. The mechanism of improvement is contraction of the phenolised wound away from the lateral nail fold, which gradually stretches and flattens the nail bed. We conclude that this technique is a simple and effective treatment for pincer nail deformity.

A clinical study of 35 cases of pincer nails

BACKGROUND

Pincer nail is a nail deformity characterized by transverse overcurvature of the nail plate. Pincer nail can affect a patient's quality of life due to its chronic, recurrent course; however, there have been no clinical studies on the pincer nail condition in Korean patients.

OBJECTIVE

The purpose of this study was to characterize the clinical findings and treatment of pincer nail. In addition, possible etiological factors were considered, and treatment efficacy was evaluated.

METHODS

The medical records and clinical photographs of 35 patients (12 males, 23 females) who were diagnosed with pincer nail between August 1, 2005 and July 31, 2009 were studied.

RESULTS

Patient age ranged from 10 to 77 (52.09±17.26) years, and there was a predominance of female (23 out of 35 patients, F:M=2:1). The mean duration of the disorder was 7.45 years (range 0.25~40); 85% had pincer nail for at least 1 year. In addition, 40% had a history of previous treatment and recurrence. There were 82.8% patients with the common type of pincer nails. The most commonly involved nails were both great toenails. Among 35 patients, nail grinding was started in 30 patients, and 25 patients showed clinical improvement with nail grinding. The width index increased and the height index decreased after treatment. The mean follow up period was 8.42 months (range 1~27), and 7 patients showed recurrence after 8.8 months (range 2~20). Among 35 patients, 5 patients were treated with nail extraction with matricectomy, and the symptoms resolved immediately. The mean follow up period was 7.6 months (range 0~19), and recurrence was not observed. Onychomycosis was also present in 37.1% of patients, and itraconazole pulse therapy for 3 months was added.

CONCLUSION

The results of this study demonstrate the clinical features of pincer nail in Korean patients. The findings show that the common type of pincer nail was most common, and nail grinding as a conservative treatment greatly improved pincer nails despite a risk of recurrence. When onychomycosis was also present, oral antifungal therapy added to nail grinding resulted in a more rapid change in nail thickness and clinical improvement.