Nail Psoriasis : Causes , Symptoms , Treatment options

Nail psoriasis is common in psoriatic patients, particularly in patients with joint involvement. It has a significant impact on their quality of life, affecting physical activities as well as causing emotional and social impairement. The disease is often refractory to treatment, and available therapeutic agents affect the matrix or the nail-bed features with variable success. The recent design of the Nail Psoriasis Severity Index allows a more standarized approach regarding outcome assessment. In this review, we assess treatment options of nail psoriasis and empahsize the importance of selecting modalities according to the particular psoriatic nail features.

Causes of Nail Psoriasis
Usually, nail psoriasis occurs in patients with psoriasis. It is associated with Psoriatic arthritis (arthritis in fingers and toes), occurring in about 50-85% of these patients.
Signs and Symptoms of Nail Psoriasis
Nail psoriasis may affect the nail plate, nail bed (the tissue under the nail), nail matrix (the tissue from which the nail grows), nail folds, cuticle, and the bones at the end of the fingers. Signs of nail psoriasis vary according to the part of the nail affected and the nature of the deformity.
It is rare that a person develops psoriasis only on the nails and nowhere else on the body. There are five general types of Nail psoriasis; these changes may occur alone or simultaneously. They include:
Pitting: A deeply pitted nail caused by the deficiencies in nail growth due to psoriasis in the nail matrix, characterized by loss of parakeratotic cells from surface of nail plate.
Discoloration of the nail bed (yellow or yellowish pink) resembling drops of oil under the nail plate, referred to as an “oil drop” or “salmon patch” caused by psoriasis in the nail bed.
The appearance of a white area separating and lifting from the nail plate, caused by pockets of air where the nail bed is lifting from the nail bed. This is referred onycholysis, and may be accompanied by inflamed skin around the nail.
Crumbling and total loss of the nail due to psoriasis causing weakening of the nail matrix.
Psoriasis of the finger and toenails can resemble other conditions such as chronic fungal infection or inflammation of the nail bed.
Nail Psoriasis Treatment Options
Your treatment will depend on the type of nail psoriasis you have and how severe it is. If you have psoriasis that affects other parts of your body, the treatments your doctor recommends to alleviate those symptoms may also help your nail psoriasis. Other options for nail psoriasis include:
Topical treatments. These medications are applied to the nails:
Dovonex (calcipotriene), a form of synthetic vitamin D3 that can slow cell growth
High-potency corticosteroids, anti-inflammatory medications that can be applied to the nails temporarily
Cordran (flurandrenolide), a steroid medication that is in the form of a tape that can be applied to the nails
5-fluroruracil cream, a topical treatment that often helps with nail pitting
Tazorac (tazarotene), a topical medication that can slow cell growth
Corticosteroid injections. In some cases, having steroid medications injected into your nail bed or matrix can temporarily improve nail psoriasis symptoms.
Phototherapy. A type of phototherapy known as PUVA (psoralen and ultraviolet light A) uses UVA light plus a light-sensitizing medication called psoralen. When your skin or nails are sensitized to UVA rays, excessive cell production can be slowed. PUVA for nail psoriasis may involve taking psoralen orally or painting it onto the nails before UVA treatment.

Cosmetic nail repair. Sometimes surgery or the application of a urea compound is necessary to remove deformed nails. In cases where nails are excessively thick and long, they can be filed down. If nails are discolored or otherwise cosmetically deformed, the deformity can be covered up with nail polish or artificial nails. And pitted nails can be buffed and polished.

Nail Psoriasis : Causes and Treatment

Psoriasis can affect both fingernails and toenails. The percentage of those with psoriasis who have nail involvement is thought to be up to 50%. In psoriatic arthritis this may rise to 80%. For some unknown reason fingernails are more often involved than toenails. For many people, nail psoriasis is often mild and causes few problems.

The nails are part of the skin, so it is perhaps not surprising that a skin disease such as psoriasis can affect the nails. No one knows why some people get nail involvement and others don’t. Nails grow from the nail root (matrix), which is just under the cuticle. In people who develop nail psoriasis it is involvement of the nail root that causes pitting and ridging of the nails.
These are the most common changes in nail psoriasis:
Pitting of the nails – the surface of the nail develops small pits, looking rather like the surface of a thimble. The number of pits can vary from one to dozens.
Onycholysis – the nail becomes detached from the underlying nail bed and a gap develops under the nail. When it starts there is a white or yellowish patch at the tip of the nail, and this then extends down to the cuticle. The gap between the nail and the nail bed can become colonised by particular bacteria, such as pseudomonas, which can then produce a dark green pigment. The nail can become infected and discoloured and can easily be mistaken for melanoma under the nail.
Subungual hyperkeratosis – a chalky substance accumulates under the nail. The nail becomes raised and can become tender, especially when the surface of the nail is pressed. Subungual hyperkeratosis of the toenails can be particularly uncomfortable because when wearing shoes the nail may be put under constant pressure.
Discolouration – this may be seen as unusual nail colouration, such as yellow-brown.
Onychomycosis – a fungal infection that can cause thickening of the nails. This could be present alongside nail psoriasis and can be confused in diagnosis. If diagnosed correctly it can be treated with systemic antifungal medication. It is estimated that approximately 35% of people who have nail psoriasis may also have a fungal infection that could make the nails worse. Treating the fungal infection may not have any effect on the clearance of nail psoriasis.

Some nail changes are caused by using systemic retinoid medication, which can help the skin but may result in formation of very thin nails which do not appear normal. These nail changes can take several months to grow out only after retinoids are stopped.