Onycholysis

What is it?

Onycholysis is the separation of a fingernail or toenail from its pink nail bed. The separation occurs gradually and is painless.

The most common cause of onycholysis is trauma. Even slight trauma can cause onycholysis when it happens repetitively — for example, the daily tapping of long fingernails on a keyboard or counter. Onycholysis also can be caused by manicure tools that are pushed beneath the nail to clear dirt or smooth the nail.  Too much moisture also can cause the problem.

Some medical conditions can cause onycholysis, generally by changing the nail's shape or the contour of the soft tissue bed beneath it. In these situations, the nail cannot attach smoothly to the nail bed.

• Fungal infections of the nails thicken the tissue immediately underneath the nail plate and cause edge of the nail to lift.
• Certain skin conditions, including allergic reactions and psoriasis are common causes of onycholysis.
• After exposure to some medicines (notably medicines from the psoralen, tetracycline or fluoroquinolone groups) the nail can react to sun exposure by lifting away from its bed.
• An overactive thyroid gland and iron deficiency are two other medical conditions that are associated with onycholysis.
• Working with your fingers or toes in a wet environment.

Symptoms

A nail that has lifted from its bed at its end can have an irregular border between the pink portion of the nail and the white outside edge of the nail. A greater portion of the nail is opaque, either whitened or discolored to yellow or green. Depending on the cause of onycholysis, the nail may have collected thickened skin underneath the edge of its nail plate, and the nail plate may have a deformed shape with pits or indentations in the nail surface, a bent nail edge or coarse thickening of the nail.

Diagnosis

Your doctor will be able to confirm that you have onycholysis by examining your fingernails or toenails. If the cause of onycholysis is not obvious, your doctor will note additional characteristics of your nails, such as their shape and color, the presence of indentations in the nail surface, and the appearance of the skin under and around the nail. He or she also will examine you to check for evidence of skin rashes or thyroid problems.

If your doctor suspects that a fungal infection is the cause of nail changes, he or she might scrape a sample of tissue from beneath the nail plate. This sample can be tested in a laboratory to check for fungus.

Expected duration

Nails are slow to grow and take time to repair themselves. The portion of nail that has separated from the skin surface beneath it will not reattach. Onycholysis only goes away after new nail has replaced the affected area. It takes four to six months for a fingernail to fully regrow, and twice as long for toenails. Some nail problems are difficult to cure and may affect the nail appearance permanently.

Prevention

Some preventive measures will make onycholysis less likely to occur:

• Cut nails to a comfortable length so that they will be less likely to endure repeated trauma from tapping in everyday use.
• Wear rubber gloves to avoid repetitive immersion in water. Nails expand after they are exposed to moisture and then shrink while drying, a cycle that can make them brittle. Keeping your nails dry also will help prevent fungal infections.
• Avoid frequent exposure to harsh chemicals, such as nail polish remover.

Treatment

Because the portion of nail that has lifted away from its bed may catch on edges when you move abruptly, it is a good idea to trim the nail close to the place where it separates from the nail bed. A physician can help you do this.

Treatment for onycholysis depends on the cause of the problem:

• Treatment for hyperthyroidism and iron deficiency can permit the nails to regrow normally.
• Some treatments for psoriasis may improve nail health.
• Oral prescription medicines are available to treat fungal nail infections. However, they have potential side effects, can be costly and are not always covered by insurance.

When to call a professional

Onycholysis is not an urgent problem and can be discussed with your doctor during a routine visit.

Prognosis

Nail changes are usually not permanent, but they can take many months to go away even after effective treatment.