Psoriasis of the nails
Nail changes occur in up to 50 percent of people with psoriasis and at least 80 percent of people with psoriatic arthritis.
The nail problems most commonly experienced by psoriasis patients are:
- Pitting—shallow or deep holes in the nail
- Deformation—alterations in the normal shape of the nail
- Thickening of the nail
- Onycholysis—separation of the nail from the nail bed
- Discoloration—unusual nail coloration, such as yellow-brown
Nail treatments
Because psoriasis affects the nail when the nail is being formed, it is difficult to treat. The matrix, where the nail is formed, is difficult to penetrate with topical medications. Injections of steroids into the nail bed or matrix area have been used with varying results. The pain of the injections must be weighed along with the possibility of the relief being only temporary.
The major treatments specifically for nail psoriasis are:
- Topical treatments—Dovonex, Tazorac, corticosteroids, steroid impregnated tape (Cordran), 5-fluorouracil;
- Intralesional—injection of steroids into each affected nail;
- Phototherapy—PUVA (psoralen applied as "paint" or taken by mouth to increase sensitivity to ultraviolet light A);
- Cosmetic repair—nails deformed by psoriasis may be removed surgically or with a strong urea compound. Long, thick nails can be scraped and filed down. Color changes can be covered with nail polish, and pitted nails can be buffed and polished. In some instances, artificial nails may be warranted.
When people have severe, generalized psoriasis, the nail treatment is determined by the treatments they are already receiving for other parts of the body. If a person's condition requires methotrexate, for example, nails are likely to improve. Similar results may be expected from other systemic psoriasis treatments that are dramatically effective.
Oral retinoids, such as Soriatane, can be beneficial for skin lesions of psoriasis, but usually result in the formation of very thin nails that are not normal in appearance. The nail changes caused by retinoids resolve several months after retinoids are discontinued.
In people whose psoriasis is sufficiently severe that treatment with PUVA is warranted, nails may improve. As with systemic treatments, the nail improvement may lag behind clearance of plaques on the body by several months.
Onychomycosis, a fungal infection that causes thickening of the nails, may be present with nail psoriasis. It can be treated with systemic antifungal agents. About one-third of people who have nail psoriasis also have a fungal infection that could actually be triggering their psoriasis or making the psoriasis worse. It is important to note that treating the fungus may not cause the nail psoriasis to clear.
A double-blind, randomized study of Tazorac gel in the treatment of nail psoriasis found that once-daily applications of the medication can significantly reduce separation of the nail from the nail bed (in occluded and non-occluded nails) and pitting (in occluded nails). In the study, some patients' nails were wrapped (occluded) with a plastic film after the medication was applied.
Another study published in the July 2003 issue of the British Journal of Dermatology found that of 25 patients treated with Tazorac, 19 showed a good clinical response. The study lasted for 12 weeks and people were treated once a day at bedtime.
Nail care
In most cases, the nails should be trimmed back to the point of firm attachment with manicure scissors. Nails should be kept as short as possible. Loose nails continue to be subjected to strain as they rub against surfaces. It is important to protect your nails from damage because trauma will often trigger or worsen nail psoriasis. One way to do this is to wear gloves while you are working with your hands. Vigorous cleaning and scraping under the nails may break the skin where the nail is attached. Be gentle when using instruments for cleaning under the nails.
Soaking your nails can help. Try three capfuls of tar bath oil in a bowl of warm water. Soak your fingers for 20 minutes and then rub moisturizer into each nail. A variety of tar bath oils and moisturizers are available at local pharmacies.
If your nails are mostly intact, application of a nail hardener or artificial nails can improve their appearance. However, sensitivity reactions to glues and chemicals may be a problem. Rule out any sensitivity reactions before using artificial nails. Be aware that a manicurist may be reluctant to apply the nails to badly eroded fingernails.
Toenails can be improved by soaking the feet for 10 minutes in a tub of warm water, gently filing the thickened part of the toenail with an emery board, and using good clippers to cut off a small piece at a time. The aim is to cut straight across the toenail to help keep it from becoming ingrown. Wearing roomy shoes leaves room for the toes and helps avoid the friction that can cause toenails to thicken.
Updated October 2005
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