Clinical and Sociodemographic Characteristics of Patients with Ingrown Nails

Abstract

Background: Ingrown nail is a common health problem that significantly affects daily life due to its painful nature. The purpose of this study was to reveal the clinical and sociodemographic characteristics of ingrown nails. Methods: The clinical and sociodemographic characteristics of patients older than 18 years presenting with ingrown nail were investigated. Results: Two hundred six patients aged 18 to 77 years (mean age, 39 years; female to male ratio, 1.45) were included in the study. A total of 729 lesions were evaluated (718 ingrown nails were on the feet and 11 were on the fingers). A family history of ingrown nail was present in 7.6% of the participants. Of the 206 patients, 26.7% were treated with surgical methods for ingrown nails previously and experienced recurrence. Ingrown toenails were in the hallux in 81.3% of patients, and 52% were on the lateral margin. Incorrect nail-cutting habits (73.5%), poorly fitting shoes (46.2%), excessive angulation of the nail plate (35.8%), obesity (34.1%), trauma to the feet (24.3%), pregnancy (23.8% of women), hyperhidrosis (16.8%), and lateral deviation of the nail plate (9.9%) were closely associated with ingrown nails. Conclusions: This study revealed the clinical and sociodemographic characteristics of ingrown nails. The study data will be useful in preventing the development of ingrown nail and recurrences after treatment by identifying and then eliminating conditions establishing a predisposition to it.

Ingrown nail is an important health problem because of the disturbance it can cause to patients' daily, working, and social lives. Studies on ingrown nails have concentrated on the treatment. There is not enough comprehensive study of the clinical and sociodemographic characteristics of ingrown nail.

Ingrown nail is a condition frequently seen in dermatology clinics, usually in the hallux and in young adults. The prevalence is uncertain, but one screening study in the United States reported ingrown nail in 24 people per 1,000.[1]

The soft tissue in the nail sulcus is not normally in contact with the nail edges. The balance between the lateral nail sulcus and nail body is impaired by the factors that cause ingrown nails. The lateral nail edge grows or is pushed toward the lateral nail fold. This initially causes pain, and if the process continues, foreign-body reactions, bacterial infections, drainage, and abscess formations occur. In the final stage, hypertrophy and pyogenic granuloma develop on the lateral nail edge. Severe pain, difficulty in walking, and interruption of working and social life then ensue.[2]

The purpose of this study was to reveal the clinical and sociodemographic characteristics of adult patients with ingrown nail. Good investigation of the clinical and sociodemographic characteristics of ingrown nail and the factors facilitating the condition will make it possible to prevent subsequent recurrences, to prevent the disease by eliminating these factors, and to treat ingrown nail with conservative methods in the early period.

Materials and Methods

This study was performed with 206 patients older than 18 years presenting with ingrown nails. We investigated the clinical and sociodemographic characteristics of ingrown nail and the factors that can lead to or facilitate it.

In light of previous studies,[3-5] ingrown nail was classified into three clinical stages: stage 1 includes erythema and mild edema in the periungual region and mild pain when pressure is applied; stage 2, worsening symptoms, purulent secretion, and local infection findings; and stage 3, severe worsening of symptoms, hypertrophy of the lateral nail fold, and granulation tissue.

The type of ingrown nail was evaluated using the Ross classification.[6] In type 1 (subcutaneous ingrown toenail), the nail plate has a normal structure. Ingrown toenail generally occurs due to incorrect cutting. The nail plate punctures the lateral nail fold and leads to inflammation. In type 2, ingrown nail occurs because the lateral nail folds are hypertrophic. The nail plate punctures the overgrown lateral nail fold, leading to foreign-body reaction and inflammation. In type 3, the lateral margins of the nail plate exhibit extreme curvature to where the nail plate curves in such a way as to enter the lateral folds, causing inflammation (pincer nail).

Results

There were 206 patients aged 18 to 77 years (mean age, 39 years), 122 women (59.2%) and 84 men (40.8%), included in the study. The female to male ratio was 1.45. When patients were evaluated in terms of occupations requiring prolonged periods in a standing position, 31.2% were desk job officers; 30.7% were housewives; 20.8% were health personnel or members of the police, military, or other groups spending long periods standing; and 15.8% were students. A further 1.5% of patients were unemployed.

The frequencies of the conditions establishing a predisposition to ingrown nails are shown in Table 1. When patients were asked about drug use, pincer nail and consequent ingrown toenail associated with β-blocker use (metoprolol) was determined in only one patient. Symptoms lasted less than 1 month in 6.3% of patients, 1 to 6 months in 19.5%, 6 to 12 months in 24.4%, 1 to 2 years in 11.2%, 2 to 3 years in 5.9%, 3 to 4 years in 2.9%, 4 to 5 years in 6.8%, and longer than 5 years in 22.9%.

Table 1. Frequency of the Conditions Establishing a Predisposition to Ingrown Nails 

Table 1. Frequency of the Conditions Establishing a Predisposition to Ingrown Nails 

No previous treatment for ingrown nail has been received by 73.3% of patients, and 21.9% used surgical methods other than chemical matricectomy, 4.3% had undergone matrix cauterization with phenol, and 0.5% had received matrix cauterization with sodium hydroxide. Of the patients who had previously received surgical treatment, 70% underwent nail extraction once, 16% twice, and 12% more than twice, but symptoms subsequently recurred.

A total of 729 lesions were observed in 206 patients (718 ingrown nails on the feet and 11 on the fingers). Ingrowth was present in four edges in 42.7% of patients, in two edges in 29.1%, in one edge in 17.5%, in three edges in 2.4%, in six edges in 2.4%, in eight edges in 1.5%, in 20 edges in 1.5%, and in 10, 12, and 24 edges in 1% each. Accordingly, ingrowth was observed in a maximum of four edges in 91.7% of patients.

Ingrown nail was determined in only one nail in 45.1% of patients, in two nails in 46.6%, in three nails in 1.9%, in four nails in 1.9%, in five nails in 1%, in six nails in 1%, in ten nails in 1.5%, and in 12 nails in 1%. On the basis of these findings, ingrown nail was present in one or two nails in 91.7% of patients.

Ingrown toenails were in the hallux in 81.3% of patients (left foot, 41.5%; right foot, 39.8%). When lesion locations were evaluated on the basis of nail edges, 52% were on the lateral margin and 48% on the medial margin.

A total of 718 ingrown toenails were observed: 41.4% were stage 1, 44.5% were stage 2, and 14.1% were stage 3. In terms of ingrown fingernails, five (45.4%) of the 11 lesions were stage 1 and six (54.6%) were stage 2. Stage 2 was most common in the toes, and stage 3 was least common. Stage 2 was most common in the fingers, and no stage 3 lesions were observed.

Ingrown nails were 52.9% type 1, 8.8% type 2, 37.1% type 3, 0.5% combined types 1 and 2, and 1.7% combined types 2 and 3. In terms of ingrown fingernails, type 1 was observed in only one of the 11 patients (9.1%), and type 3 was observed in the remaining ten patients (90.9%).

Discussion

Ingrown nail is a clinical condition that can be seen at any age but that more commonly appears in early adulthood; it is caused by the lateral margin of the nail growing or being pressed into the lateral nail fold.[7-9] It is highly uncomfortable and painful for the patient and leads to workforce losses.

Studies on ingrown nails in the literature have focused on the treatment. There was only one study about the epidemiology of this condition in PubMed, and that study was performed in the United States in 1990.[1] Therefore, the data in the present study were compared with the data in that study and studies about treatment.

Studies concerning ingrown nail have reported that the condition is more common in females than in males.[1,10,11] In the present study, the incidence of ingrown nail was approximately 1.45-fold higher in women than in men. The greater incidence of ingrown nail in women can be attributed to Turkish women having a higher body mass index, to their higher numbers of pregnancies, and to their choosing inappropriate footwear.

Mean age of appearance of ingrown nail in this study was 30 years. This was in agreement with other studies from Turkey and elsewhere.[10-14] The reason for the greater incidence of ingrown nail in the fourth decade (30–40 years) is thought to be associated with an active work and sporting life, or for women having pregnancies and having higher body mass indices. The lower incidences at more advanced ages can be attributed to nail thickness increasing with age, patients receiving effective treatment before this time, and nail folds undergoing age-related atrophy.

Obesity analysis revealed obesity in 34.1% of patients with ingrown nail. One prevalence study of obesity in Turkey reported a prevalence of 22.3%.[15] The higher level of obesity compared with the general population in the present study is compatible with data from the literature evaluating obesity among the etiological factors in ingrown nail.[2,9,16] Obesity is thought to affect the development of ingrown nail by increasing pressure on the toes.

Venous pressure in the lower extremities increases during pregnancy due to pressure on the pelvic veins and retention of water and salt in the body, and edema may, thus, occur in these regions. Ingrown nail may occur more easily in pregnant women in association with increasing edema.[17,18] Ingrown nail commenced after pregnancy in 23.8% of female patients in this study.

One of the factors known to lead to ingrown nail is trauma.[9,19] A history of trauma was determined in 24.3% of the patients in the present study. The high level of history of trauma is compatible with previous studies emphasizing that trauma to the foot may be a significant factor in the development of ingrown nail.

Another etiological factor reported in the literature concerning ingrown nail is taking part in sports.[9,19] A level of 20.5% was determined in the present study.

One of the most important factors known to lead to ingrown nail is the use of unsuitable shoes and socks. Tight shoes or socks can lead to penetration of soft tissue through compression of the lateral part of the nail. Inflammation and foreign-body reactions may, thus, be seen in this region. Unsuitable shoes were worn at the high level of 46.2% in the present study. The use of inappropriate footwear, such as shoes with pointed tips, or socks causes recurring trauma in parallel to increasing age and is one of the main causes of ingrown nail.[6-9,19,20]

A correlation between manner of nail cutting and ingrown nail has also been reported in several previous studies, and this is emphasized as one of the most commonly observed etiological factors.[6-9,16,19,20] Angled cutting of the lateral part of the nail leads to spicule formation. Spicules become embedded in the distal lateral nail fold as the nail is regenerated, and foreign-body reaction thus ensues. In conclusion, cutting the nail either very short or at an angle leads to the corners of the nail being located in a more proximal position and, thus, to these corners growing inward toward the depth of the fold. In the present study, 73.5% of patients cut their nails in a rounded manner.

Examination of the literature published concerning familial history shows that some studies have determined a higher incidence of ingrown nail in first- and second-degree relatives compared with a control group.[7,12,21] Family history is thought to reflect a familial nail bed or toe pattern.[12] These patients have been shown to have a hypertrophic nail fold and to exhibit medial rotation of the toes. A family history was present in 7.6% of the patients in the present study.

Hyperhidrosis impairs pedal hygiene by leading to maceration, and this can give rise to infections in the foot. Edema resulting from infections can also facilitate ingrown nails.[7,9,12,22] Hyperhidrosis was encountered in 16.8% of the present patients with ingrown nail. Compared with the prevalence of hyperhidrosis in the general population (3%), it may be concluded that hyperhidrosis is much more common in patients with ingrown nail.[22,23] This is also compatible with previous studies emphasizing that hyperhidrosis may be a significant etiological factor in ingrown nail.

The incidence of fungal and bacterial infections is high in feet with poor hygiene, and this is also thought to facilitate ingrown nail.[7,12,16] Impaired pedal hygiene was observed in only two patients in this study. Impaired hygiene was, thus, not observed in 99% of patients. We attribute the low level of poor pedal hygiene in this study to pain occurring in the foot after one instance of ingrown toenail leading to patients taking much greater care over foot hygiene. However, it must also not be forgotten that factors leading to frequent infections in the feet can also prepare the ground for ingrown nail.

Ingrown toenail can also develop in association with the use of certain drugs. Ingrown toenail has been reported to develop in patients taking drugs used in the treatment of human immunodeficiency virus, such as lamivudine and the indinavir-ritonavir combination, β-blockers, and cyclosporine.[24-26] One patient in the present study developed pincer nail and associated ingrown nail after starting β-blocker (metoprolol) therapy due to paroxysmal atrial tachycardia. The nail deformity in this patient resolved after discontinuation of the drug.

When the present patients were asked about systemic diseases that might be associated with ingrown nail, the most noteworthy condition was diabetes mellitus (7.5%). The high incidence of bacterial and fungal infections in diabetic patients is thought to create a disposition to ingrown nail. In addition, vasculopathy in diabetic patients has been reported to lead to thickening in the nail plate by impairing blood flow.[2,8]

Lateral deviation of the nail plate can lead to ingrown nail by compromising the relation between the nail plate and the nail bed and by exacerbating irritation between these structures.[2,18,27] Lateral deviation in the nail plate was determined in 9.9% of the present patients. Excessive angulation of the nail plate can also lead to a disposition to ingrown nail[18] and was observed in 35.8% of the present patients.

In terms of duration of lesions, ingrown nail had been present for 1 year or less in 50.2% of patients. This also suggested that the pain caused by ingrown nail prompted patients to seek medical assistance earlier compared with other diseases.

To determine which methods are used in the treatment of ingrown nail, we first investigated whether patients had previously received any treatment, and if so, which. The findings showed that matrix cauterization had been performed with phenol in 4.3% of patients and with sodium hydroxide in 0.5%; surgical methods other than chemical matrixectomy were applied in 21.9% of cases; and 73.3% of patients had not previously received any treatment. Patients were also evaluated in terms of previous nail extraction: 18.7% of patients had undergone one extraction, 4.8% two extractions, and 3.2% more than two extractions. Assessment of all these findings together shows that ingrown nail has a recurring nature and difficulties can sometimes be experienced in treatment.[8,28] The lateral margins of the nail matrix being located very close to the periosteum may lead to this part of the matrix sometimes being impossible to remove during surgery and, thus, to new nail formations and ingrown nail. In addition, success levels in treatment of ingrown nail can vary, depending on the techniques used and on the experience of the practitioner.

Factors capable of causing internal compression in the nail bed can increase pressure between the nail plate and the nail bed, and this can also facilitate ingrown nail. Potential causes of internal compression, such as subungual lesions, malformed phalanges, and arthropathies, were investigated in the framework of this study. Malformed phalanges were observed in 1.1% of patients and subungual lesions in 0.5%. Although the statistical values obtained are not particularly significant, it should still be remembered that factors capable of causing internal compression can also give rise to ingrown nail.

Orthopedic disorders that impair the biomechanics of the foot can also give rise to ingrown nail by increasing friction between the nail plate and bed.[28] Orthopedic disorders observed in the patients in this study included proximal synechiae in the bilateral second and third toes, Rubinstein-Taybi syndrome, pes planus, pes echinovarus, and hammer toe. The absence of other factors in these patients that might give rise to ingrown nail emphasized the importance of these factors in ingrown nail.

Some nail changes can also create a disposition to the development of ingrown nail. Some changes observed in advanced age (onychogryphosis, onychauxis, and subungual hyperkeratosis) and conditions capable of impairing the shape of the nail body, such as pincer nail and onychomycosis, impair the proportions between the nail plate and fold and result in increased pressure between these two structures.[16,28] Subungual hyperkeratosis was observed at a level of 16.9% in this study, pincer nail at 7.9% and comorbid subungual hyperkeratosis and pincer nail at 12.4%.

Ingrown nail in the present study was most common in the hallux (81.3%). This finding was compatible with the literature.[2,18,28] The reason for ingrown nail frequently being observed in the hallux is thought to be the fact that weight during walking is to a large degree borne by the hallux. This force can propel soft tissue upward around the distal part of the nail edge. The hallux is, thus, most affected by interaction between the foot and the shoe and by abnormal pedal biomechanics.

Ingrown nail is a condition that almost always affects the toes. However, it may also be seen in the fingers, albeit rarely. In the present study, ingrown nail in the fingers was observed in only four patients (total of 11 ingrown nails). The reason for the much lower incidence of ingrown nail in the fingers compared with the toes is reported to be that the weight of the body is loaded onto the toes, which are, thus, more exposed to trauma.[2,9,18,28] In the toenails, the matrix curves in such a way as to form a hemisphere over the terminal phalanx. In addition, due to mediolateral convexity, a larger part of the nail plate is covered by the lateral nail fold compared with in the fingers. When ingrown nail is seen in the fingers, trauma must particularly be investigated because the cause is generally traumatic.[2]

When lesion locations according to the nail margins were assessed, 52% of ingrowths were observed on the lateral margin. A higher incidence of ingrown nail in the lateral margins has been reported in the literature.[6-8,12,27] When the patient is standing, the hallux performs a medial rotation, returning to its former position when the foot is lifted off the ground. At the same time, the body of the nail moves laterally, meaning that ingrown nail is observed more in the lateral aspect.[12] In addition, inside the shoe the second toe is pushed toward the lateral margin of the hallux, and pressure, thus, increases along the lateral margin. This, in turn, facilitates ingrowth.[20]

In terms of stages of lesions, stage 2 was most commonly observed in the toes, and stage 3 lesions were least common. We attribute these findings to ingrown nail causing subjective symptoms such as pain and disturbance of daily life from the moment of onset, for which reason patients seek medical attention earlier than in other diseases.

Type 1 ingrown nail was most commonly observed in the present study, and in agreement with previous studies, this emphasizes the importance of nail cutting in the development of ingrown nail. In this type, the incorrectly severed portion of the nail grows directly beneath the soft tissue, leading to inflammation and irritation on the margin of the nail.[6]

Conclusions

Several factors are involved in the formation of ingrown nail. In the present study, ingrown nail was particularly associated with incorrect nail cutting habits, inappropriate footwear, excessive angulation of the nail plate, nail bed traumas, obesity, pregnancy, and hyperhidrosis. We think that these study data will be useful in the prevention of ingrown nail by revealing and then eliminating conditions creating a predisposition to it.