Overview
Psoriasis is a long-term skin condition in which skin cells grow too fast and pile up into thick, red, scaly patches, often on the elbows, knees and scalp. It is driven by an overactive immune system, is not contagious, and tends to flare and settle over time. It can also affect the nails and joints. While there is no permanent cure, many effective treatments control it well and let people live comfortably.
Symptoms
- Thick red patches covered with silvery scales
- Dry, cracked skin that may itch or bleed
- Patches commonly on the elbows, knees, scalp and lower back
- Pitted or thickened nails
- Joint pain and swelling in some people
When to see a doctor
See a skin doctor for persistent scaly patches, or if the condition is widespread, affecting nails, or causing joint pain.
Causes
An overactive immune system with a genetic tendency. Flares can be triggered by infection, stress, skin injury, some medicines and smoking.