Total Nail Avulsion for Pincer Nail: Report of Two Cases

Summary:

Pincer nail is a common condition characterized by excessive transverse curvature of the nail that causes pain, cosmetic problems, and functional limitation. Surgical treatments include correction of the nail bed and distal phalanges, which have shown good outcomes but are difficult to perform in general clinics because of their high invasion. Conservative treatments require special devices, which may be difficult to keep on hand in general clinics. We report two cases of pincer nails successfully treated by total nail avulsion. The patient in case 1 is a 66-year-old woman. She had a pincer nail on her right third toe that was painful. Total nail avulsion was performed on the nail, and taping was performed after surgery. Three months later, a new flattened nail grew. The curvature index was improved from 2.43 to 1.10. The patient in case 2 is a 68-year-old woman. Total nail avulsion was performed on a pincer nail of the left second toe. Nineteen months later, the nail was flattened and she remained free from pain. The curvature index was improved from 3.62 to 1.32. In both cases, pain was soon relieved by total nail avulsion and there were no complications. Total nail avulsion does not require special devices, can be performed in a short time during outpatient treatment, and is relatively less invasive. It is also easily applied to small nails. Total nail avulsion is an effective treatment for pincer nails on the second and third toes. Future studies are needed to determine if it is equally effective for pincer nails on the first toe.

Pincer nail is a common condition in which the nails are transversally curved excessively, with their lateral edges causing pain. Pincer nail also causes cosmetic discomfort and functional limitation, but there is currently no definitive treatment for the disease. In this study, we report the good results of total nail avulsion for pincer nails on the second and third toes. The curvature index¹ (Fig. 1A) was used as an index for the severity of pincer nails.

Fig. 1.

Frontal view of case 1 before and after total nail avulsion. A, Pincer nail of the right third toe. Preoperative view. The apparent width of the nail tip is defined as W, and the traced length of the nail tip is defined as L. The curvature index is defined as L divided by W(L/W). The curvature index of this case was 2.43. B, Postoperative view. Three months after avulsion, the pincer nail has been flattened. The curvature index was 1.10.

CASE REPORT

Case 1

A 66-year-old woman had a pincer nail of her right third toe for several years. She stated that there had been a gradual onset of pain without apparent cause. Preoperative curvature index was 2.43 (Fig. 1A). After digital block anesthesia, the right third toe nail was totally avulsed. The pain disappeared the next day, and the avulsed area was epithelialized 10 days later. (See figure, Supplemental Digital Content 1, which shows the state of the third toe 10 days after avulsion. http://links.lww.com/PRSGO/D433.) At that time, the nail bed was flatter than before avulsion. Taping was instructed to prevent upward deformation of the distal nail bed, and the patient visited the clinic every month. (See figure, Supplemental Digital Content 2, which shows postoperative taping. From the dorsal tip of the toe through the flexor side, the tape was applied with traction from the medial side of the base of the toe to the dorsum of the foot. http://links.lww.com/PRSGO/D434.) Three months after the avulsion, the new nail grew to the tip of the toe, and the curvature was normalized (Fig. 1B). The curvature index was improved to 1.10.

Case 2

A 68-year-old woman was seen in the clinic for a problem of pain and deformity of the left second toe. The patient stated that she had noted the change in the transverse shape of the nail more than 10 years previously and the toe had become painful in the last year. Preoperative curvature index was 3.62 (Fig. 2A). After digital block anesthesia, the left second toe nail was totally avulsed. Pain disappeared the next day. After that, the patient stopped coming to the clinic. Nineteen months after the avulsion, she was seen in the clinic for another disease. The curvature index was improved to 1.32 (Fig. 2B). Her nail pain had not recurred. There were no complications in case 1 or 2.

Fig. 2.

Frontal view of case 2 before and after total nail avulsion. A, Pincer nail of the left second toe. Preoperative view. The curvature index was 3.62. B, Postoperative view. Nineteen months after avulsion, the curvature index was improved to 1.32.

DISCUSSION

The term pincer nail was introduced by Cornelius et al in 1968.² They performed total nail avulsion for pincer nails. The treatment of pincer nails includes surgery to flatten the nail bed^3,4 and conservative correction of the nail curvature with special devices.^5,6 The former involves surgical correction of the nail bed and distal phalanx, and is difficult to perform in general clinics because of its high invasion. It can also cause complications such as sensory disturbance of wound margin and prolonged wound healing.⁴ The latter requires special devices, which may be difficult to keep on hand in general clinics. In addition, some devices may be difficult to use on the second and third toes, which have smaller nails than first toes.

In addition to Cornelius et al, Higashi observed that pincer nails were improved by total nail avulsion and postoperative taping,⁷ but he did not present his results in a published article. To our knowledge, this is the first article that shows pincer nail deformity is improved by total nail avulsion. In the article by Cornelius et al,² it was stated that total nail avulsion for pincer nails improved pain, but the changes of nail deformity were not described. In our report, the images show that the nail curvature was improved before and after avulsion. In case 1, the nail bed was almost flattened when the nail bed became epithelialized (Supplemental Digital Content 1, http://links.lww.com/PRSGO/D433). Therefore, the mechanism by which total nail avulsion improves the nail curvature can be inferred as follows: as described by Kosaka et al,⁴ the curvature of a pincer nail is not only a result, but also causes the nail bed to deform. The deformed nail deforms the nail bed by tightening the nail bed inward, creating a vicious cycle that generates a pincer nail. Therefore, avulsion of the deformed nail can break the vicious cycle by flattening the nail bed and normalizing the newly formed nail (Fig. 1B). Although total nail avulsion requires local anesthesia, it is a relatively less invasive procedure that can be performed in about 5 minutes. It can be performed in a general dermatology clinic during outpatient hours and does not require special devices. Pincer nail is a common condition and can cause pain, so it is worthwhile that pincer nail is treated by total nail avulsion in general clinics. In case 1, taping was performed after total nail avulsion to prevent elevation of the nail bed.⁸ However, in case 2, no elevation of the nail bed was observed without taping. Because the second and third toes receive less upward pressure during walking than the first toe,⁸ taping may not be needed after total nail avulsion. In order to know whether taping is necessary or not, more cases should be compared between cases with taping and cases without taping. In addition, although we performed total nail avulsion for pincer nails on the second and third toes, it is not clear whether this result can be applied to the first toe as well. As mentioned above, the first toe can develop upward deformation of distal bed after avulsion,⁸ so total nail avulsion may be ineffective and even harmful. Future studies are necessary to determine whether this procedure is equally effective for a pincer nail on the first toe.

We have shown that total nail avulsion is a simple and effective method of improving the pincer nail curvature. The limitation of this report is that the number of cases is small and it cannot be determined that total nail avulsion is effective for all pincer nails. Therefore, more cases need to be studied to confirm the effectiveness of total nail avulsion.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.