Retronychia is a nail condition that occurs when a nail stops growing outward and instead starts growing back into the nail fold (the skin around the nail). Most common in young adult women, early symptoms include pain, redness, swelling, and changes in nail color. In later stages, new nails can start growing underneath the old nail, resulting in multiple layers of nails pushing against the original.
Retronychia often results from repeatedly applying pressure to the toenail due to wearing shoes that are too tight. An injury to the big toe or certain underlying health conditions can also cause this condition. It can be painful and affect your ability to walk.
Retronychia is commonly misdiagnosed. Ensuring you understand and recognize the cause and symptoms of retronychia can help prevent it or raise your chances of an accurate diagnosis.
Retronychia typically causes symptoms in and around the big toenail. Symptoms include:
- Redness and swelling of the skin around the nail, especially at the base near the cuticle
- Pain or tenderness near the nail
- Yellowing or thickening of the nail
- Pink, bumpy tissue growing around the nail
- Pus (thick white fluid) oozing from the nail area
- A disappearing cuticle
- A partially detached or raised nail
- Trouble walking due to pain
Eventually, layers of new nails grow and stack up underneath the old nail. Treating retronychia in its early stage may prevent it from progressing.
Causes of Retronychia
Retronychia has several possible causes. However, retronychia may occur for no apparent reason.
Ill-Fitting Shoes
The most common cause of retronychia is poorly fitting shoes. Frequent pressure from shoes that are too small or that have high heels can repeatedly injure the toenail bed, called microtraumas. Repeated microtraumas may cause the toenail to grow back into the nail fold.
You may also be at a higher risk of getting retronychia if you frequently do physical activities like running, hiking, or dancing. This is due to the constant pressure that shoes put on the front edges of the toenails.
Acute Toenail Injury
An acute toenail injury is a one-time injury that damages the toenail bed. This type of injury may include stubbing your toe, dropping something on your foot, or even getting a cat scratch.
Other Health Conditions
Certain health conditions may make you more likely to develop retronychia, including:
- Arthritis
- Thrombophlebitis (a condition where a blood clot forms in and blocks a vein)
- Compartment syndrome (a condition in which pressure around a muscle group restricts blood flow)
- Postpartum (after childbirth)
- Foot conditions that put extra pressure on your big toe, like misalignment of your toenails (when the nail moves from its original place)
Consider seeing a podiatrist (foot specialist) if you notice symptoms of retronychia, like swelling or tenderness around your big toe, or if your toenail seems to stop growing. To diagnose you, they may want to do an ultrasound, which is an imaging test to rule out other nail conditions causing your symptoms.
You should seek immediate care if you have severe pain or signs of an infection, such as pus oozing from the nail area or a fever.
Treatments for Retronychia
Retronychia treatment focuses on relieving symptoms and getting the nail to grow back normally. If you catch it early, you may be able to reverse retronychia by changing whatever caused trauma to the nail. These changes include wearing looser, flatter, or better-fitting shoes. Minimizing activities such as running, dancing, or hiking, since they can put pressure on your toes, can lower your risk.
If your retronychia symptoms continue, your healthcare provider might also recommend:
- Tape, wrap, or clip back the nail
- Wear an acrylic nail
- Apply steroids to the area to reduce swelling
In severe or chronic retronychia cases, you might need a surgery called a nail avulsion. During this surgery, your provider will remove part or all of your toenail using either a chemical solution or a scalpel (a small knife).
However, even with surgical treatment, retronychia can recur (come back). An estimated 16% of retronychia cases recur. Continuing to wear only loose or open-toed shoes is a way to prevent recurrence.
Research suggests that some people with retronychia may develop the condition due to the natural shape of their nails or feet. Other people may have underlying health conditions that contribute to retronychia, in which case it may not be preventable.
Most people can help prevent retronychia by doing the following:
- Wear well-fitting shoes with a wide toe box or open toes
- Avoid wearing high-heeled shoes
- Limit your time doing activities that put pressure on your toenails
- Correct or treat any foot conditions that put extra pressure on your big toe or toenail
Complications
Retronychia usually heals completely with the right treatment. However, nail avulsion surgery can sometimes cause complications, including:
- Nail bed retraction (the nail bed gets smaller)
- Pincer nail (where the nail becomes severely curved and pinches the skin around it)
- Micronychia (growing a smaller-than-usual toenail)
Retronychia occurs when a toenail grows back into the nail fold, resulting in pain, swelling, and nail discoloration. Repeated pressure on the toes, injury, and certain underlying health conditions usually cause the condition.
Treatment ranges from wearing proper footwear to possible nail removal surgery. You can prevent retronychia and its complications by protecting your nails. If you experience severe nail pain or signs of infection, seek medical attention immediately.
