What Causes Psoriasis
Although its causes are not fully understood, it's clear that both genes and environment play a role. Your chances of developing psoriasis go up if you have a family history of the condition -- in fact, it's the most significant risk factor for the disease. As many as one-third of people with psoriasis have a blood relative who also has it. While certain genes may make you more susceptible to psoriasis, just being genetically predisposed to it doesn't mean you'll get it.
Environmental factors also are important. People who live in colder climates are more likely to develop psoriasis, often at a younger age. Other factors that affect susceptibility include ethnicity. Psoriasis is less common in African Americans and is rare in native ethnic groups from both North and South America.
On the flip side, alcohol abuse increases the risk of psoriasis. So does smoking, which is also linked to increased severity, especially with the localized form of dangerous pustular psoriasis. Some infections, bad sunburns, and certain medications (such as beta blockers, lithium, and antimalarial drugs) seem to trigger psoriasis, too.
