What Is Nail Psoriasis?

Up to 90% of people with psoriasis are affected

women's nails

 

Gianni Diliberto/Getty Images

In This Article
Table of Contents

Unlike some manifestations of psoriasis that you can hide, psoriasis of the nails—also known as psoriatic nail disease—results in damaged, split, or lifting nails that are on full display every day. You may feel self-conscious, embarrassed, or uncomfortable, and you may even experience pain that can make it difficult to walk, jog, or do manual labor. Nail psoriasis can lead to progressive damage of fingernails and toenails.

Psoriatic nail disease typically occurs alongside the classic symptoms of psoriasis, a chronic skin disorder—namely, itching, redness, scaling, and the formation of thickened patches called plaques. If nail psoriasis occurs on its own, it is often difficult to diagnose and may be easily confused for other conditions.

Causes

Psoriasis of the nails is caused by the same autoimmune mechanisms as psoriasis of the skin. For reasons not entirely clear, the immune system will inexplicably regard normal tissues as harmful and launch an immune assault. Although the skin is the primary target, other tissues are affected as well. The ensuing inflammation triggers an acceleration in the production of cells, known as keratinocytes, in the skin, nails, and other tissues.

When this occurs in the skin, characteristics plaques can develop. In the fingernails and toenails, the overproduction of keratinocytes can cause thickening, malformation, and discoloration as the cells are produced faster than they can be shed.

According to a 2017 review in the journal Psoriasis, around half of all people with psoriasis will experience nail changes at the time of their initial diagnosis, while 90% will experience significant nail alterations at some point in their life.

Symptoms

Symptoms can vary from one person to the next and alter as the disease progresses. Among some of the tell-tale signs of nail psoriasis are:

  • Pitting of the nail surface
  • Lines and furrows (Beau's lines) that run side to side rather from cuticle to tip
  • Thickening of the nail (subungual hyperkeratosis)
  • Yellowish-red dots under the nail, known as oil drops or salmon patches
  • White patches on the nail (leukonychia)
  • Tiny blacks lines that run from the tip to cuticle (splinter hemorrhages) caused by burst capillaries
  • Lifting of the nail plate (onycholysis), usually moving from tip to cuticle
  • Crumbling and brittle nails
  • Redness in the white arch at the base of the nail (spotted lunula)
  • Arthritis in the finger or toe with nail damage (psoriatic arthritis)

Diagnosis

Like psoriasis of the skin, psoriatic nail disease is primarily diagnosed by a physical examination and a review of the medical history (including the family's history of skin disorders). There are no blood tests or imaging studies that can diagnose psoriasis.

If the symptoms are atypical or uncertain, your doctor may take nail clippings or a tissue sample from the nail bed to examine under the microscope. When viewed in this way, psoriatic tissues will typically have cells that are dense and tightly compacted (referred to as acanthotic).

If the nails are affected by psoriasis but not the skin, the doctor will typically investigate and exclude all other possible causes to render a definitive diagnosis. Referred to as a differential diagnosis, the process may involve tissue biopsies, lab cultures, and other tests to pare down the likely causes. Among the conditions that mimic psoriatic nail disease:

  • Alopecia areata is an autoimmune disease characterized by hair loss and nail damage.
  • Lichen planus is an inflammatory condition affecting the skin, nails, and hair.
  • Onychomycosis is a common fungal infection of the nail.
  • Pityriasis rubra pilaris is a rare disorder that causes skin inflammation, the thickening of nails, and the loss of hair.

Treatment

The treatment of nail psoriasis is slow and often difficult. Since it takes around three months to regrow a fingernail and six months to regrow a toenail, successful treatments will take at least that long before the nail will start to look normal again.

Treatments may be topical, oral, injected, or any of these used in combination.

Topical Steroids

Topical steroids are sometimes used to reduce localized inflammation. While helpful in treating skin psoriasis, they can be difficult to apply to the nails. Liquid steroid drops are usually applied to the underside of the nail tip and other areas where the skin and nail meet. Overuse can lead to permanent skin thinning (atrophy) in the treated area.

Calcipotriol

Calcipotriol is a vitamin D derivative applied topically twice daily to the affected nail. It is typically available in a 50-micrograms-per-gram (mcg/g) formulation.

A 2014 review of studies from India reported that, when used for three to six months, calcipotriol creams were just as effective as topical steroids in improving nail psoriasis symptoms.

Tazarotene

Tazarotene is a topical retinoid product used to treat psoriasis and acne. Tazarotene 0.1% gel or cream applied once daily for 12 to 24 weeks has been shown to improve pitting, onycholysis, and salmon patches on both fingernails and toenails, according to a 2010 study in the Indian Journal of Dermatology.

Steroid Injections

Steroid injections are delivered in small doses directly into or near the structure of the nail unit. Triamcinolone acetonide is the most commonly used intralesional steroid, and it's typically prescribed in a single 0.1-milliliter (mL) injection given at four sites around the nail. Pain is the most common side effect of treatment.

Systemic Therapies

Systemic therapies involve medications that temper the underlying immune response that triggers nail malformation. These include older disease-modifying anti-rheumatic drugs (DMARDs) like methotrexate and Sandimmune (cyclosporine), as well as newer biologic drugs like Otezla (apremilast), Humira (adalimumab), and Cosentyx (secukinumab).

Generally speaking, systemic drugs are only used when psoriasis of the skin is moderate to severe, not when only the nails are affected.

Other Treatments

A number of other treatments are used for nail psoriasis, some of which are better than others. Although phototherapy using ultraviolet (UV) lamps has proven beneficial in treating plaque psoriasis, it only appears effective in treating oil spots in nails.

While oral retinoids like acitretin may be useful in treating nail psoriasis, their benefits are highly dose-dependent. If taken in anything but the smallest possible dose, oral retinoids may cause a worsening of symptoms, including nail crumbling and paronychia (an infection of the skin folds around the nails).

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.