The most common reason for black lines in fingernails is psoriasis, a skin disease that affects more than 4.5 million Americans.(1) It is an inherited affliction, related to the immune system; an overload of nerve messaging from the immune system causes skin to grow too fast, and can result in lesions on other parts of the body.
Variety of Nail Symptoms
Tiny black lines, reaching from the top of the nail to the root, are just one of the ways psoriasis manifests itself at the fingertips. Other nail symptoms include: a clear, yellow-red discoloration; side-to-side lines; redness of the pale arched area at the bottom of the cuticle; and more.
Surprisingly, there is no real cure for psoriasis. Once detected, the sufferer can only follow common sense safeguards such as protecting their hands, soaking them in liquids, and keeping the nails as short as possible.
High Occurrence Rate
Changes in nail appearance are experienced by 50% of psoriasis sufferers and an even higher, 80% share of arthritic psoriasis patients.(2) Cortisone injections and cosmetic surgery are too of the more dramatic ways to treat the appearance of black lines in nails, and other psoriasis symptoms.
There is also the chance that with psoriasis will come a related condition known as onychomycosis. This fungal injection thickens the nails and tends to show up in one out of every three psoriasis sufferers.
Medications that can help speed the healing of black lines in fingernails include Vitamin A and Vitamin D rich creams, steroids, and a cocktail known as PUVA.(3) However, one of the conundrums of nail psoriasis is that the affected area is quite difficult to get at, and treat. For those who suffer from both psoriasis and arthritis, systematic therapy is sometimes prescribed. This pill or injection relies on medications methotrexate, Enbrel, Humira, and Remicadel. The only real prevention technique, for those predisposed to it by genetics, is to keep the nails dry.
(1) University of Alabama at Birmingham – Nail Psoriasis, Retrieved May 26, 2011 from http://www.health.uab.edu/17791/
(2) National Psoriasis Foundation – Specific Locations: Hands and Feet, Retrieved May 26, 2011 from http://www.psoriasis.org/NetCommunity/Page.aspx?pid=445
(3) WebMD – Living with Psoriasis, Retrieved May 26, 2011 from http://www.webmd.com/skin-problems-and-treatments/psoriasis-8/nail-psoriasis