Nail psoriasis is one of the seven types of psoriasis. Unlike the other types which affect the skin or the joints (arthritis psoriasis), nail psoriasis only affects the nails.
However, patients with nail psoriasis often also have a form of skin psoriasis.
Psoriasis of the nails is also commonly found in patients with psoriatic arthritis.
Terms used to describe the structure of the nail.
Listed below are a few terms often used when describing the symptoms of nail psoriasis.
Nail Plate - the nail plate is the upper, hard part of nail. The nail plate is made of a keratin layer which protects the tips of the fingers and toes and the underlying nail bed.
Nail Bed - the nail bed is the soft area under the nail plate.
Nail Matrix - the nail matrix is the area at the base of the fingernail or toenail from where the nail is produced.
Hyponychium - the hyponychium is the thickened epidermis which lies under the free edge of the nail.
Nail Psoriasis Diagnosis
A psoriasis nails diagnosis is usually made by doctor who looks at the appearance of the nails.
Other conditions and diseases may have similar symptoms to nail psoriasis. Where there is the chance of another condition being present a nail biopsy may be taken to confirm the psoriasis nail diagnosis.
Nail Psoriasis Symptoms
Beau's lines – these are deep grooved lines which run horizontally across the nail plate running from one side to the other. These ridges and indentations which transverse the nail plate are thought to develop following a temporary pause in the cell division within the nail matrix.
Crumbing of the nail plate – psoriasis affects the underlying nail structure weakening the nail plate.
Discoloration of the nail bed – referred to as salmon patch or oil drop due to the red to yellow discoloration in parts of the nail bed.
Leukonychia – also known as 'white nails', leukonychia is a white discoloration which appears on the nails.
Onycholysis – the separation of the nail from the nail bed. This is a gradual and painless process. The underlying nail plate whitens.
Pitting – small indentations in the surface of the nail plate. They are usually white in appearance.
Subungual hyperkeratosis – this term refers to scaling under hyponychium.
Although psoriasis of the nails can severely affect the nails appearance, nail psoriasis does not have serious physical consequences.
Nail Psoriasis Treatment
There is no cure for nail psoriasis.
Nail psoriasis treatment focuses on reducing the symptoms of this disease as nail psoriasis symptoms can make the nails appear unsightly causing distress to those concerned.
As the nail takes a long time to grow, these treatments often require extended periods of application and during the long treatment intervals the nail may have improved by itself.
Psoriasis nail treatments include:
Calipotriol solution – this may help psoriasis nails if applied regularly over long periods of treatment.
Corticosteriod solution or ointment
Psoralen and UVA
Systemic treatment – nail psoriasis treatments taken orally include ciclosporin, methotrexate and retinoids.
Surgical removal of the nail – using chemical or surgical avulsion therapy the entire nail may be removed.
However this is not usually recommended as the new nail which grows has a good chance of being as badly affected or even worse than the nail it replaces.