What is psoriatic arthritis? Psoriatic arthritis is a condition that causes swelling and pain in joints and the places where tendons and ligaments attach to bones. Most people who develop psoriatic arthritis already have psoriasis (a skin disease), but a small number have joint pain before the skin rash.
An NIH Health Capsule article. Scoliosis is a disease that causes the spine to curve. It can result in an abnormal s-shaped or c-shaped curve. Anyone can get scoliosis. But it’s most common in children age 11 and older.