Author: Vanessa Ngan, Staff Writer, 2003. Updated by A/Prof Amanda Oakley, February 2016.
Nail psoriasis is nail disease associated with psoriasis. It is also known as psoriatic nail dystrophy.
Patients with nail psoriasis may be of any age or race. Nail dystrophy is often precipitated or aggravated by trauma.
Nail psoriasis arises within the nail matrix. The specific pathogenesis of nail psoriasis is unknown.
Nail psoriasis can affect any part of one or more nails. There are often scaly plaques on the dorsum of the hands and fingers due to associated plaque psoriasis. Signs depend on the part of the nail affected. Its severity may or may not reflect the severity of the skin or joint psoriasis.
Nail psoriasis is unsightly. It can also lead to:
Psoriatic nail disease is readily recognised in a patient with current or prior plaque psoriasis. It is frequently confused with fungal nail infection. Fungal infection can also complicate nail psoriasis.
If in doubt, or antifungal treatment is planned, nail clippings and scrapings of subungual debris should be sent for potassium hydroxide microscopy and fungal culture.
A biopsy of the proximal nail matrix is occasionally needed to confirm the diagnosis of nail psoriasis, particularly if dystrophy affects a single nail and a tumour is a possible explanation. The biopsy can lead to permanent nail deformity.
It is difficult to treat nail psoriasis effectively.
Topical treatment must be applied to the nail matrix and hyponychium for months or years, and its effects are often disappointing. Options include:
Other options include:
Note: acitretin thins the nail plate and reduces its speed of growth, which can be helpful or not, depending on the type of nail psoriasis.
Chemical or surgical avulsion therapy, i.e. complete removal of the nail, is occasionally recommended. A risk is that the regrowing nail may be as badly or more severely affected than prior to the procedure.
At this time, we do not know how to prevent nail psoriasis. Avoidance of trauma is essential.
Nail psoriasis varies in severity over time. In some patients, it resolves completely spontaneously or as a response to systemic treatment. In others, it persists long term.
See the DermNet NZ bookstore.
© 2018 DermNet New Zealand Trust.
DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice.