Psoriatic Nails (Nail Psoriasis)

What nail psoriasis looks like

Psoriasis can affect two parts of the nail:

Nail matrix (where the nail grows) changes

• pitting: small, pinpoint dents on the nail surface; the most common sign
• leukonychia: white spots
• ridges and grooves across the nail
• crumbling of the nail plate
• red spots in the half-moon (lunula)

Nail bed changes

• onycholysis: the nail lifts off the nail bed, often starting at the tip, leaving a white or yellow area
• oil drop or salmon patches: yellow-red discoloration under the nail
• subungual hyperkeratosis: thick, chalky debris under the nail
• splinter hemorrhages: tiny dark lines

Fingernails are affected more often than toenails. Several nails are usually involved.

Nail psoriasis vs fungal nail infection

Both can occur together, because psoriatic nails are more prone to fungal infection. Testing nail clippings before treatment avoids unnecessary antifungals. See onychomycosis.

Who gets it

• people with psoriasis, particularly with longer-standing or more severe disease
• people with psoriatic arthritis
• sometimes nail psoriasis is the only sign of psoriasis

Nail psoriasis is linked to inflammation at the attachment points of tendons near the end finger joint, which is why it often predicts psoriatic arthritis. Report joint pain, swelling or morning stiffness to your doctor.

Diagnosis

• examination of nails, skin, scalp and joints
• nail clippings for fungal microscopy and culture
• dermoscopy to look at nail features
• nail biopsy occasionally, if the diagnosis is uncertain
• assessment for psoriatic arthritis, including x-rays or ultrasound if joints are affected

Treatment

Nails grow slowly, about 3 mm a month for fingernails, so treatment usually takes 4 to 6 months for fingernails and 12 to 18 months for toenails to show full results.

Nail care

• keep nails short and trimmed
• wear gloves for wet work and gardening
• avoid manicures that push back cuticles or clean under nails aggressively
• moisturize nails and cuticles
• avoid injury, which can trigger new psoriasis (the Koebner phenomenon)
• nail polish can camouflage pitting; avoid acrylic nails

Topical treatments

• potent topical corticosteroids, often combined with calcipotriol (vitamin D analog), applied to the nail folds and under lifted nails
• tazarotene (a topical retinoid)
• tacrolimus

Injections

Corticosteroid injections into the nail fold can improve matrix changes in a few severely affected nails.

Systemic treatment

For many affected nails, nail psoriasis with significant skin psoriasis or with psoriatic arthritis:

• methotrexate, cyclosporine, apremilast, acitretin
• biologic medicines targeting TNF, IL-17 or IL-23, which can clear nails substantially, often within 6 to 12 months, and also treat psoriatic arthritis
• oral TYK2 or JAK inhibitors for some patients

Other

Laser and light-based treatments have limited evidence.

Outlook

Nail psoriasis is chronic but treatable. With modern systemic and biologic treatments, many people achieve near-clear nails. Untreated, nails may become painful, thick and difficult to use, and nail psoriasis may signal joint involvement that needs treatment to prevent damage.

Frequently asked questions

What does nail psoriasis look like?

Common signs are tiny pits on the nail surface, yellow-red "oil drop" spots, white patches, ridges, crumbling, thickening and nails lifting from the nail bed. Several fingernails are usually affected.

How can I tell nail psoriasis from nail fungus?

Nail psoriasis often causes pitting and oil-drop spots and usually affects several fingernails, often with psoriasis elsewhere. Fungus more often starts in one toenail with thick yellow nails and athlete's foot. A nail clipping test confirms which it is.

Is nail psoriasis a sign of psoriatic arthritis?

Nail psoriasis is strongly linked to psoriatic arthritis; most people with psoriatic arthritis have nail changes. If you have nail psoriasis and joint pain, swelling or morning stiffness, see a doctor promptly.

What is the best treatment for nail psoriasis?

For a few nails, strong steroid creams with calcipotriol or steroid injections into the nail fold work well. For many nails, or with skin or joint psoriasis, systemic medicines and biologics are most effective. Treatment takes months because nails grow slowly.

Can nail psoriasis be cured?

There is no permanent cure, but treatment can clear nails significantly or completely. Psoriasis may flare again, so ongoing treatment or maintenance therapy is often needed.