Nail pitting can be caused by different illnesses but the most common cause is from psoriasis. Nails may develop deep or shallow holes and become thickened or deformed in shape. Sometimes there is discoloration of the nail and it may appear yellow/brown or the nail may separate from the nail bed, which is called onycholysis.
One classic sign of nail psoriasis is called an oil drop or salmon patch nail where there is a yellow/red discoloration under the nail that resembles an oil drop. Treatment of psoriasis of the nail can be challenging since it takes so many months for the nail to grow out but there are therapies to try.
Facts about psoriasis:
Of the seven million people in the U.S. with psoriasis, 10 to 50 percent of people have their finger or toenails affected. About 10 to 20 percent of people who do have nail involvement go on to develop arthritic psoriasis, which can affect the joints at the ends of the fingers called distal interphalangeal (DIP) joints. People with psoriatic arthritis typically have further nail changes that may include: beau’s lines which are transverse lines, leukonychia which are white patches, or splinter hemorrhages due to breakage of capillaries under the nail.
The cause of psoriasis is unknown though it is thought that family history, immune system changes, environmental influences and vascular system factors contribute.
Treatments for psoriasis of the nails:
According to about.com, Tazarotene is the most successful treatment for nail psoriasis. Tazarotene is a vitamin A derivative that is applied as a cream or a gel. The medication is applied once a day and it may take two to 12 weeks before improvement may be noticed. Tazarotene can be combined with other topical treatments and phototherapy.
If Tararotene is unsuccessful in treating the nail psoriasis, then intralesional steroids, which are injected directly into the root of the nail, may help. It may take three months of once a month injections for healthy nails to grow.
PUVA treatments have been successful in treating nail psoriasis and show improvement in three to six months.