Brittle nails and psoriasis: what to know

Nail psoriasis can produce pits, ridges, thickening, discoloration, crumbling or separation from the nail bed. It may affect fingernails, toenails, or both, and it can appear with skin or joint symptoms, although nail changes may also occur on their own. Repeated wet work, detergents, manicures, picking and minor trauma can weaken the nail plate. A fungal nail infection is another possibility; it often causes thickened, discolored or crumbly nails and may need a different treatment.

Keep nails short and file rough edges in one direction. Wear gloves for cleaning or prolonged contact with water, then dry the hands and nails carefully. Avoid biting, scraping beneath the nail, aggressive cuticle cutting and covering damaged nails with extensions. Do not start antifungal or steroid treatment based on appearance alone. A clinician may inspect the nails, skin and joints and may test nail material when infection is possible. Treatment is chosen according to the cause and can take time because the damaged nail must grow out.

Arrange a medical review if brittle nails persist, involve several nails, or come with scalp or skin plaques, morning joint stiffness, swelling or pain. Seek prompt care for spreading redness, warmth, pus, marked tenderness, fever, or a dark streak that is new or changing. A sudden nail injury, bleeding under the nail, or nail separation should also be assessed, especially if the cause is unclear.

Could this be nail psoriasis, a fungal infection, or damage from an irritant? Do I have signs of psoriasis elsewhere or joint involvement? Would a nail sample or other test help? Which nail-care products and treatments are suitable for me?