Psoriasis is an autoimmune disease. Instead of fighting infection, your body’s natural defense system attacks healthy tissue. You’re more likely to get erythrodermic psoriasis if you already have plaque psoriasis, especially if it’s unstable. That means the raised, scaly patches don’t have well-defined edges -- but it also affects people who’ve never had the disease. It can appear if you suddenly stop taking your oral psoriasis medication. Other triggers include:
- Alcoholism
- Drug reaction
- HIV
- Infection
- Oral steroid medicine
- Severe sunburn
- Stress