Psoriasis is a long-term skin condition that causes inflammation and rapid skin cell buildup. The most common form, plaque psoriasis, appears as red patches covered with silvery scales. Other types include guttate psoriasis with small drop-shaped spots, pustular psoriasis with pus-filled blisters, inverse psoriasis affecting skin folds, and erythrodermic psoriasis, a rare but severe form that can require emergency care.

Although psoriasis affects the skin, it is linked to the immune system. In people with psoriasis, immune cells mistakenly attack healthy skin cells, causing the skin to renew too quickly. Genetics can also increase the risk, and the condition often runs in families.

Several factors may trigger flare-ups or worsen symptoms. Common triggers include stress, alcohol, infections, skin injuries, and certain medications. Symptoms can vary from mild irritation to painful cracking, itching, and widespread inflammation depending on the type and severity.

Psoriasis is not contagious, meaning it cannot spread from person to person. Doctors usually diagnose it through a physical examination and, in some cases, a skin biopsy. While there is currently no cure, treatments such as creams, light therapy, and medications can help control symptoms and improve quality of life.