Ingrown Toenails

In this blog post, Cypress foot and ankle specialist Dr. Christopher Correa discusses causes and treatments of ingrown toenails. As the name implies, an ingrown toenail impinges on the neighboring nail fold, causing inflammation, swelling, and pain. Minor ingrown nails can often be treated at home with anti-inflammatories and soaking. If an ingrown nail persists or continues to recur after home treatment, an infection known as a paronychia can form. This term refers to an infection in the soft tissue immediately surrounding the nail. Infections of an ingrown toenail can become quite severe and should be treated by a podiatrist. To get a better understanding of why a toenail can ingrow, let’s take a closer look at the relevant anatomy.

Nail Anatomy

Nail anatomy consists of the nail plate itself, the nail matrix, and the nail bed. The nail matrix is located at the proximal end of the nail plate, which contributes to 80% of nail growth. The nail bed is a thin layer of tissue that exists directly under the nail, serving to cover the bone and contributing to 20% of nail growth. The skin located at the most proximal part of the nail is known as the epinychium, and the connection of the distal nail plate to the distal toe is known as the hyponychium. This is also colloquially known as “the quick”. The skin folds on either side of the nail are known as the nail folds. The shape of the nail unit and size of the nail folds are largely determined by genetics; however, disorders such as toenail fungus, nutritional imbalances, certain systemic illnesses, or damage to the nail matrix and bed can lead to deformity and thickening of the nail, increasing the risk for ingrown toenails.

Causes of Ingrown Nails

Causes of ingrown toenails vary and can stem from poor/irregular anatomy, nail fungal changes (nail dystrophy), trauma, shoes that are too small, or an overly aggressive pedicure, to name a few. Generally speaking, the causes fit into one of two broad categories: 1. a misshapen nail that impinges on the nail fold as it grows out, or 2. inflammation or swelling of the surrounding soft tissue that causes the tissue to swell and push itself up against the nail, causing an "ingrown". Misshapen toenails typically come from trauma, fungal infections, or genetics. Inflammation can come from an overly aggressive pedicure, having one's toes stepped on during sporting activities, wearing shoes that are too small, or equinus (a tight calf muscle), just to name a few. Tight calf muscles contribute to excessive dorsiflexion of the big toe during the swing phase of gait, leading to repetitive microtrauma to the nails. If there is a known cause of why the nail ingrew, then future ingrown nails can be avoided.

Treatments for Ingrown Toenails

If there is no previous history of ingrown toenails and there is a known cause of the ingrown (trauma, overzealous pedicure, sports injury, etc), then a slant back procedure may be all that is required. This is a simple procedure where the distal, growing portion of the nail is clipped out. This is a noninvasive process and can usually be done without anesthesia. For more aggressive or recurrent ingrown nails, a partial nail avulsion may be necessary. This treatment serves as a way to “hit the reset button” and is used to clear out the ingrowing portion of the toenail, allowing for the inflammation and infection to resolve, paving the way for a healthy, normal toenail to grow back in. During this procedure, the toe is numbed with local anesthetic, and the offending nail border is removed from the tip of the nail all the way back to the epinychium. Oftentimes, only about 10-20% of the nail border is all that needs to be removed. The procedure takes about 10 minutes, and patients need only to wear a large bandage on their toe for the rest of the day. Pt are typically able to return to regular shoes and activity the following day with little need for pain medications. Should we be dealing with a recurring ingrown toenail, then this procedure can be converted to a more permanent version with the addition of Phenol 89%. This chemical allows for the killing of only the exposed portion of the nail bed and matrix, allowing for no further growth of that section of toenail. Typically, this procedure is 85% effective. It is worth mentioning that this procedure is typically not performed in the presence of infection because it can drastically reduce the efficacy of the Phenol. The reason the procedure does not work as well in the presence of infection is that infection changes the pH of the tissue, causing the chemical to be less effective. Due to this, if you present to the clinic with a severely infected ingrown toenail, you may require a week of antibiotics before a matrixectomy can be performed. After a successful matrixectomy, the remainder of the toenail grows normally, and patients are left with a skinnier nail, which often is not noticeable to the untrained eye. The only difference in post op care between these procedures is that the matrixectomy requires the patient to soak their toe in Epsom salt and warm water for 10-15 minutes daily for 14 days. The reason for this is that the Phenol creates a chemical burn, causing serous drainage. If left alone, this drainage can harden to a crust that traps bacteria inside, increasing the risk for infection. For this, we require soaking after a matrixectomy and not after a partial nail avulsion. Matrixectomies may incur slightly more pain the following day than their counterpart; however, it is usually nothing that cannot be handled with over-the-counter anti-inflammatories.

Nail Trauma

In cases of acute trauma to the nail, it may be necessary to remove the entire toenail. This is often due to the partial or near-complete detachment of the toenail, leading to bleeding that is trapped under the nail plate. Blood under the nail can be a source of infection and, in sufficient quantity, needs to be removed so the soft tissues can heal. The primary reason for the removal of the toenail is that the trapped blood serves as a nidus for infection. Typically, the threshold for removal is when 50% of the toenail is separated from the nail bed with blood infiltration. Another reason the nail may need to be removed is laceration of the nail bed with or without an underlying toe fracture. If a fracture is present, this is considered an open fracture, and it is very important to drain the blood from the area and close any laceration in a timely fashion to prevent infection of the bone. Thankfully, toenail bed injuries are easily treatable by a medical professional and, if treated in a timely fashion, usually avoid infection. Lower-level trauma, such as long-standing micro trauma from shoe gear irritation seen in long-distance runners, may cause bleeding or bruising under the nail, which could lead to detachment of the nail months later. This level of injury is less severe and usually results in the nail falling off on its own as a new toenail grows in to replace the damaged toenail. Typically, no laceration or pooling of blood occurs, and no surgical removal of the toenail is necessary.

In diabetic patients or patients with blood flow issues (peripheral vascular disease), toenail/ toe pain should always be evaluated by a podiatrist. Severely restricted blood flow can lead to toe pain, which is assumed to be an ingrown toenail. Damage to the surrounding nail unit in a vasculopath can start a chain reaction of tissue death that leads to gangrene of the toe or worse. Diabetics and vasculopaths are strongly urged not attempt self-care of their toenails and feet and are advised to follow up with a podiatrist regularly. If you are experiencing foot or ankle pain, make an appointment with the experts at Select Foot and Ankle Specialists and take the first step toward recovery today.