There are several types of psoriasis. Symptoms for each type may vary, but the major symptoms are:
- Raised, bright red patches of skin, often covered with loose, silvery scales, usually on the knees, elbows, or low back.
- Tiny areas of bleeding when skin scales are picked or scraped off (Auspitz's sign).
- Mild scaling to thick, crusted plaques on the scalp.
- Itching, especially during sudden flare-ups or when the psoriasis patches are in body folds, such as under the breasts or buttocks.
- Discolored or pitted nails.
Other symptoms of psoriasis may include:
- Similar plaques in the same area on both sides of the body (for example, both knees or both elbows).
- Flare-ups of many raindrop-shaped patches (guttate psoriasis).
- Joint swelling, tenderness, and pain (psoriatic arthritis).
- Psoriasis patches that appear after an injury, such as a cut, a burn, or too much sun. This is called Koebner's phenomenon. Because this response is common, it's important for people with psoriasis to avoid irritating or injuring their skin.
Several other skin conditions have symptoms similar to psoriasis. And some medicine reactions can cause symptoms (such as reddened skin) similar to psoriasis. Talk to your doctor about the medicines you are taking.