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An ingrown toe nail is best described as a foreign body reaction with mild infection. The toe nail grows into the skin and acts as a foreign body. The adjacent skin reacts to the nail as if it were a foreign body (splinter or piece of glass.) Continued pressure by the nail against the skin causes inflammation and a soft tissue infection. The skin envelops the nail and a low-grade infection ensues in an attempt to reject the nail. The infection causes pain, drainage, and enlargement of the surrounding skin.
- Redness (erythema) adjacent to the nail
- Drainage and odor associated with the localized infection
- Pain with direct pressure to the site of infection
The most common reason we develop ingrown nails is due to improper trimming of the nail. The nail is very weak when twisted (torsion.) If the nail is trimmed so that a small spur, called a spicule, is left on the border of the nail, the nail will continue to grow, forcing the spicule into the skin. As the skin responds to this "foreign object" it becomes inflamed and sore. The area adjacent to the nail will become increasingly more difficult to trim, and so begins the vicious cycle that we call an ingrown nail.
The majority of ingrown nails are found on the great toe. Pain is usually tolerable until the nail is bumped or stepped on. Ingrown nails are extremely common in adolescent boys and in women 2-3 months postpartum. Young boys seem to have little regard for regular hygiene and pregnant women have a difficult time reaching their feet during the last several months of their pregnancy, not to mention the additional burden of their feet swelling.
Nail is an elastic, transparent layer of keratin. It is surrounded on two sides by soft skin referred to as the periungual folds. The base of the nail is called the eponychium and the distal tip of the nail is called the hyponychium. Nail cells are created in a small envelope called the nail matrix. An ingrown nail occurs when the nail grows into the periungual fold.
Causes and contributing factors
The shape of the nail can be a contributing factor for ingrown nails. Pincer nails (as shown to the left), a term used for nails that have a pinched appearance, put pressure on the periungual folds. As shoe pressure is exerted on the nail, the edges of the nail push into the skin just as the weight of something put on a table pushes through the legs of the table to the floor.
Other contributing factors that may cause ingrown nails include trauma to the nail, pressure from adjacent toes, and the shape or profile of the forefoot in relationship to the shape of the toe box of the shoe. Medical conditions, such as fungal infections or psoriasis, can change the shape of the nail and contribute to ingrown nails.
The differential diagnosis for an ingrown nail includes the following:
Benign soft tissue tumor
Lister corn or callus
Malignant soft tissue tumor
Ingrown toenails are treated in much the same manner as a splinter would be. Antibiotics and soaking can help to reduce the inflammation associated with the ingrown nail, but until the foreign object (ingrown nail) is removed, the stalemate between the nail and adjacent skin will continue. Removal of the offending border of nail is required.
Many authors have suggested the "proper" way to trim the nail, but in actuality, every nail is a bit different from the next nail. Therefore, it's most important to trim the nail with quality nail trimmers in a way that it is not going to irritate the periungual fold. Trimming the nail straight across may work for some but is ineffective for others. Some advocate cutting a groove or V in the distal tip of the nail. This is also ineffective. Cotton under the edge of the nail has been tried, even metallic clips that "lift" the nail, but each of these will fail in time unless the offending border of the nail is removed. NailEase may help to lift the edges of the nail in a limited number of cases. Many pregnant women develop ingrown nails due to their inability to reach their feet. NailEase is a great product for them since they are poor surgical candidates until they deliver.
The technique used to treat infected ingrown nails is called a phenol-alcohol procedure (P&A procedure.) This procedure is performed in an office setting under a local anesthetic. After the toe is numbed and cleaned with a disinfecting agent, a thin margin of nail is removed. Phenol, which is 77% carboxylic acid, is applied to the nail matrix to kill the cells that produce that small margin of nail. The phenol is then flushed out with alcohol. Patients can return to a Band-Aid and regular shoes the next day.
The interesting thing about the phenol-alcohol procedure is the lack of pain experienced by patients following their surgery. This is due to the fact that phenol has a topical anesthetic property that lasts for 2-3 weeks. Although the procedure will drain for several days, the benefit of using phenol is significant. Phenol is best known as the active ingredient in Chloroseptic Mouthwash Spray. In Chloroseptic, phenol is used in a more dilute concentration but has the same effect in that it inhibits sore throat pain.
Other surgical procedures may be used with or without phenol and include the use of silver nitrate or a CO2 laser to destroy the nail matrix cells. The decision to remove one border, both borders or the entire nail should be discussed with your doctor.
The following images show the steps involved in correcting an ingrown nail with a phenol alcohol (P&A) procedure. Image 1 shows administration of local anesthesia. Once the toe has been anesthetized, the foot is prepped with a Betadine or comparable antiseptic solution. Image 2 shows a small tourniquet (Penrose drain) around the toe to inhibit bleeding (hemostasis.) A nail splitter is being used to create a clean split to remove just the borders of the nail. Image 3 shows a hemostat being used to remove the nail. The nail bed is then scraped with a small curette to physically destroy the nail matrix. In image 4 we see the application of phenol. Phenol application is normally done 3 times for 5-10 seconds each application. Image 5 shows the final bandage. This procedure is completed in 10 minutes and is performed in an office setting. Post-op care varies, but steps are taken to promote drainage of the nail and may include Epsom Salt soaks or application of steroid/antibiotic drops. Patients return to a normal shoe the day after surgery wearing just a 1" Band-Aid. Healing takes 10-14 days.
When to contact your doctor
Persistent ingrown nails that do not respond to conservative care need to be evaluated and treated by your podiatrist. Long-standing infected ingrown nails may progress to infect the bone of the toe. Therefore, treatment of chronic ingrown nails should be performed in a timely manner.
References are pending.
Author(s) and date
This article was written by Myfootshop.com medical director Jeffrey A. Oster, DPM.
Competing Interests - None
Cite this article as: Oster, Jeffrey. Ingrown Toe Nail http://www.myfootshop.com/article/ingrown-toe-nail
Most recent article update: December 6, 2018.
Ingrown Toe Nail by Myfootshop.com is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
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