Psoriasis is a skin condition that tends to flare up from time to time. About half of the people who have psoriasis also have changes affecting their nails. Psoriatic nail disease is very variable in appearance and severity.
Psoriasis affecting the nails can be mild and not need any treatment. More severe nail psoriasis is often difficult to treat but modern treatments can be effective. Without effective treatment, severe nail psoriasis can cause a lot of discomfort and distress.
What is psoriasis?
Psoriasis is a common condition where there is inflammation of the skin. It typically develops as patches (plaques) of red, scaly skin. Once you develop psoriasis it tends to come and go throughout life. A flare-up can occur at any time. The frequency of flare-ups varies. There may be times when psoriasis clears for long spells. However, in some people the flare-ups occur often. Psoriasis is not due to an infection. You cannot pass it on to other people, and it is not cancerous.
The severity of psoriasis varies greatly. In some people it is mild with a few small patches that develop and are barely noticeable. In others, there are many patches of varying size. In many people the severity is somewhere between these two extremes.
See also separate leaflet called Psoriasis.
What is psoriatic nail disease?
Psoriasis can affect fingernails and toenails. There are different types of nail changes that can occur. These changes include:
- Pitting of the nails - small pits appear on the surface of the nail. There may be one pit or many pits on the surface of a single nail.
- Onycholysis - the nail separates from the skin underneath the nail. At first this looks like a white or yellow patch at the tip of the nail. This patch gradually gets bigger and reaches the base of the nail. The gap between the nail and the skin underneath the nail can become infected and change colour.
- Subungual hyperkeratosis - chalk-like material builds up under the nail. The nail becomes raised and often tender.
- The colour of the nail may change, such as turning to yellow-brown.
- Fungal nail infections can occur with psoriatic nail disease. Fungal nail infections can cause thickening of the nails.
Pictures of the different types of psoriatic nail disease can be seen on the DermIS and DermNet NZ websites (see Further Reading & References section below).
How common is psoriatic nail disease?
About 1 in 50 people have psoriasis at some time in their life. It can first develop at any age, but it most often starts between the ages of 15 and 30 years, or after the age of 40 years.
Nail changes occur in about half of all people with psoriasis and in about 4 in every 5 people with psoriatic arthritis (see separate leaflet called Psoriatic Arthritis).
Only a few people have psoriatic nail disease without having psoriasis affecting the skin.
How is psoriatic nail disease diagnosed?
The diagnosis of psoriatic nail disease is usually made by the appearance of the affected nails. Occasionally, a nail biopsy is needed to confirm the diagnosis.
What can you do to help improve psoriatic nail disease?
- Keep your fingernails and toenails short.
- Keep your nails dry.
- Protect your nails by wearing gloves when doing any manual work.
- Avoid a manicure of the base of the nail. This may cause an infection.
- Avoid false nails.
- Nail varnish can be used to cover up pitting. Varnish containing acetone should not be used, as it can cause damage to the nail.
- If you have painful toenail psoriasis then you should see a podiatrist.
What treatments are available?
Mild nail disease which isn't causing discomfort does not need any treatment. If the nail disease is severe and causing problems then your doctor will refer you to see a skin specialist for advice and treatment.
Treatments for nail psoriasis include:
- Treatments applied to the nail, which include steroids, salicylic acid, calcipotriol or tazarotene. Local treatments applied to the nail are often not very effective.
- Antifungal treatment - this may be required for fungal nail infection if this is also present.
- A steroid injected into the nail - this may be effective for some types of nail psoriasis but it is painful.
- Phototherapy (light therapy) - psoralen plus ultraviolet light A (PUVA) treatment is effective for some types of nail psoriasis but not for pitting of the nail.
- Removing an affected nail - this can be done by applying a special type of ointment and then covering the nail for seven days. Otherwise the nail can be surgically removed using local anaesthetic.
If nail psoriasis is severe and not helped by the treatments listed above then a powerful medicine which can suppress inflammation is sometimes used. For example, methotrexate, ciclosporin, acitretin, infliximab, etanercept, efalizumab, ustekinumab or adalimumab. There is some risk of serious side-effects with these medicines, so they are only used on the advice of a specialist.
What is the prognosis (outlook) for psoriatic nail disease?
Psoriatic nail disease can be difficult to treat and so can continue to cause discomfort. The appearance of the affected nails can also sometimes cause distress.
The treatment of severe psoriatic nail disease is now improving with modern medicines.
Psoriatic nail disease can also be mild, not need any treatment and can be hidden with nail varnish.
Further help & information
Dr Colin Tidy
Dr Colin Tidy
Dr Hayley Willacy