Nail psoriasis is one of the many forms of presentations of the chronic auto-immune skin condition called psoriasis. It has been reported that 50% of people who have psoriasis have exhibited signs and symptoms of nail involvement. About 80% of patients with psoriatic arthritis also have nail psoriasis. Elderly patients with psoriasis are most likely to develop nail psoriasis.
This presentation is characterized by fingernails and toes involvement; with the fingernails more commonly affected.
The nails are extensions of the skin. They are part of the integumentary system and are made of a tough protein called keratin. The nail consists of the nail plate, the nail matrix and the nail bed below it, and the grooves surrounding it.
Parts of the Nails
- Nail matrix – Sometimes called keratinous membrane or matrix unguis, is the tissue which the nail protects. It is the part of the nail that contains nerves, lymph, and blood vessels. The matrix is responsible for producing cells that are used to build the nail plate.
- Lunula – Which means small moon, is the visible part of the matrix, the whitish crescent-shaped base of the nail. It is most visible and prominent in the thumb and least on the little finger.
- Nail Bed – The skin beneath the nail plate. Like all skin, it is composed of two layers: the dermis and epidermis.
- Nail Sinus – The location of the nail root. It originates from the growing tissue below—the matrix.
- Nail Plate – The hard part of the nail. In common usage, the word nail refers to this part only.
- The Free Margin – Or distal edge, is the front margin of nail corresponding to the abrasive or cutting edge of the nail.
- Hyponychium – Informally known as the “quick”, is the tissue found under the nail plate at the junction between the free edge and the skin of the fingertip. It forms a seal that protects the nail bed.
- Eponychium – A small band of tissue that extends from the back of the nail wall onto the base of the nail. It is commonly called the cuticle, which actually is the layer formed into the newly formed nail plate by the eponychium. Both the eponychium and the cuticle form a protective seal. The cuticle is composed of dead tissue while the eponychium is the living one and should not be touched.
- Nail Wall – The fold overlapping the sides and the near end of the nail.
- Paronychium – The border tissue around the nail.
There are several changes that occur when the nails are affected by psoriasis. These changes are the following:
- Pitting of the nails – Pits start to form along the surface. These pits vary in number–from a single one to multiple thimble-like deformations.
- Onycholysis – Refers to the detachment of the nail bed, starting from its far end and lateral attachment. It starts as a yellowish-white patch from the tip of the nail then extends down to the cuticle.
- Subungual hyperkeratosis – It is the accumulation of keratin-based chalky material under the nail. The nail may become tender and may cause discomfort in performing activities of daily living.
- Yellowish-brown Discoloration – This unusual discoloration usually signify poor nutrition or an abnormality in the formation of the nail tissues.
- Onychomycosis – A fungal infection that results to nail thickening. It may occur with or without but is usually associated with psoriasis.
Nail psoriasis is challenging to treat for the reason that topical medications would be less potent and have difficulty penetrating the nail. Injecting corticosteroids have been used with varying results.
There are also other methods that are considered extreme like removal of the nails and systemic medications. Removal of the nails generally leads to abnormal regrowth.
Systemic treatment looks promising as it would treat the psoriasis flare-up and the nail condition at the same time. The setback with systemic treatment is it has too many adverse effects as it affects also the other organs and tissues of the body.
Tips on Nail Care
Nail involvement in patients with psoriasis may cause cosmetic and activities of daily living problems. With the signs and symptoms of nail psoriasis, they may appear to be unsightly to most people and may affect the self-esteem of the patient.
Prehensile and grasping motions may also be affected, therefore limiting the hand activities. The pain, itchiness, and general discomfort may cause limitation of hand actions and mobility.
Here are several tips to remember when encountering problems related to nail psoriasis:
- Always keep the nails short. This would prevent adding further injury to the nails.
- When trimming the nails, always cut straight across to prevent ingrown regrowth.
- Use cotton gloves for cosmetic as well as protective purposes.
- Use moisturizers to to lessen the flaking and breakage of the skin.
- Always keep the affected areas clean and moisturized. Soak the hands and feet on warm water for about 10 minutes to soften the nails and remove the accumulated debris. This would soften the nails which would be ideal for cleaning and trimming.