Why does nail psoriasis cause discoloured nails?

Nail psoriasis can affect the matrix, the nail bed or both. Changes in these areas may make the nail look yellowish, brownish or patchy, and a small gap beneath the plate can create a pale or oil-drop-like area. Ridges, pits, crumbling or separation may accompany the colour change. Discoloured Nails is a common presentation of Nail Psoriasis, but fungus and injury can resemble it. A clinician may inspect the skin, joints and nails together and may test for fungus when the appearances overlap.

Keep nails short and file rough edges instead of picking at them. Protect hands from repeated wet work with suitable gloves and moisturise the surrounding skin after washing. Avoid cutting cuticles or using harsh removers on an irritated nail. Treatment may target the nail, nearby skin or wider psoriasis, so follow the plan given for your pattern of symptoms. Mention joint stiffness, swelling or morning pain because these details can affect the assessment.

Arrange a review for a new or persistent colour change, especially if the nail separates, becomes tender or starts to crumble. Seek prompt care for warmth, swelling, drainage, spreading redness or fever, which can suggest a separate infection. A new dark streak or pigment extending onto the surrounding skin needs medical assessment. Contact a clinician sooner if nail symptoms occur with painful or swollen joints.

Could psoriasis explain the colour change, or should fungus be tested? Which nail and skin treatments are suitable? What joint symptoms should I report, and how can I protect the nail while it grows?