Half of all the patients suffering from psoriasis have fingernail involvement, appearing as punctate pitting, nail thickening, or subungual hyperkeratosis. Damage to the nail bed by the pustular psoriasis can at the end result in loss of the nail. Small indents in the nails ("pitting") are the most common nail changes, other changes include lifting up of the nails ("onycholysis"), discoloration, thickening and crumbling.
The probable nail shape changes in psoriasis fall into some general categories that may occur singly or all in unison:
Firstly - The nail plate is deeply pitted, probably due to defects in nail growth caused by psoriasis. Secondly - The nail has a yellow to yellow-pink discoloration, probably due to psoriatic involvement of the nail bed. Thirdly - White areas appear under the nail plate. These are air bubbles marking spots where the nail plate is becoming detached from the nail bed (onycholysis). There may be reddened skin around the nail. Fourthly - The nail plate crumbles in yellowish patches (onychodystrophy), probably due to psoriatic involvement in the nail matrix. Fifthly - The nail is entirely lost due to psoriatic involvement of the nail matrix and nail bed. Sixthly - The nails are often surrounded by inflamed skin, and may crumble easily. In some cases, the nail may detach from the nail bed.
Since psoriasis affects the nail when the nail is being formed, it is difficult and quite a task to treat. The nail matrix, where the nail is formed and developed, 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 measured along with the possibility of the relief being only meager and temporary.
Different treatment options for nail psoriasis are as follows:
- Cosmetic and surgical repair-nails deformed by suffering from psoriasis may be removed surgically or with some chemical compounds such as strong urea compound. Long, thick nails can be scraped and filed down. Nail polish can be used for hiding the color changes and pitted nails can be buffed and polished. In some of the cases, artificial nails may be suggested.
- Intralesional- injection of steroids into each affected nail;
- Topical treatments- Dovonex, Tazora, corticosteroids, steroid impregnated tape (Cordran), 5-fluorouracil;
- Phototherapy- PUVA (psoralen applied as "paint" or taken orally to increase sensitivity to ultraviolet light )