Nail Psoriasis: Causes, Symptoms, Diagnosis, Treatment

Up to 90% of people with psoriasis are affected

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 to fingernails and toenails.

Nail psoriasis typically occurs alongside the classic symptoms of psoriasis, a chronic skin disorder: 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.

This article reviews the causes, symptoms, and treatment of nail psoriasis. It also contains photos of nail psoriasis so that you have a better sense of what it looks like.

What Causes Nail Psoriasis?

Nail psoriasis is caused by the same autoimmune mechanisms as skin psoriasis. 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.

Because of its autoimmune nature, nail psoriasis cannot spread to someone else.

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 of Nail Psoriasis

Symptoms of nail psoriasis can vary from one person to the next and alter as the disease progresses.

Nail pitting due to nail psoriasis
NEJM.org

Some of the telltale signs are:

  • Pitting of the nail surface (see photo of nail psoriasis patient above)
  • Lines and furrows (Beau's lines) that run side to side rather than 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 the 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)

While nail psoriasis symptoms may appear on both the nails of the toes and fingers, the latter is more common. It usually affects a few digits, rather than just one.

This photo contains content that some people may find graphic or disturbing.

Psoriasis of the nails
Psoriasis of the nails. Trevor Knowles / Getty Images 

How It's Diagnosed

Like psoriasis of the skin, psoriatic nail disease is primarily diagnosed by a physical examination and a medical history review (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 healthcare provider 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 healthcare provider 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 nail psoriasis:

  • 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.

Nail Psoriasis 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 to affected nails 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 to treat nail psoriasis. 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 to treat nail psoriasis 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).

Frequently Asked Questions

  • How long does it take nail psoriasis to clear up after treatment?

    Once the nail is damaged, you have to wait for it to grow out. On the hand, nails regrow in about three months. Nail psoriasis in toenails can take six months to resolve because of their slower growth rate.

  • Can you use nail polish with nail psoriasis? Acrylics?

    You can use nail polish to cover up nail psoriasis. People with psoriasis of the nails should never apply artificial nails. Fake nails or tips can damage nails, prompting a flare-up of nail psoriasis.

  • Can nail psoriasis be caused by stress?

    Yes and no. Stress does not cause nail psoriasis, but it can trigger a flare-up. Psoriasis of the nails is an autoimmune condition. Stress is a common trigger for autoimmune disease symptoms.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Psoriasis Foundation. Hands, feet & nails.

  2. American Academy of Dermatology. What is nail psoriasis, and how can I treat it?

  3. American Academy of Psoriasis. 7 Nail care tips that can reduce nail psoriasis.

  4. American Academy of Dermatology. Are triggers causing your psoriasis flare-ups?

Additional Reading