Causes and Risk Factors:
1. Autoimmune Disorder: Psoriasis is primarily an autoimmune disorder, where the immune system mistakenly attacks healthy skin cells, speeding up the skin cell turnover process.

2. Genetic Predisposition: Family history plays a significant role in the development of psoriasis. Certain genetic mutations and variations increase the likelihood of developing the condition.

3. Environmental Triggers: Factors such as stress, infections (particularly streptococcal infections), skin injuries (like cuts or burns), and certain medications (such as beta-blockers or lithium) can trigger or exacerbate psoriasis symptoms.

4. Immune System Dysfunction: Abnormalities in the immune system, including overactive T cells and cytokines (proteins that play a role in inflammation), contribute to the development and persistence of psoriasis.

Types of Psoriasis:
1. Plaque Psoriasis: The most prevalent type, marked by red, elevated areas coated in a layer of dead skin cells that has turned silvery-white.

2. Guttate Psoriasis: Small, dot-like lesions that often develop after a bacterial or viral infection and primarily affect children and young adults.