What Increases Your Risk

Many doctors believe that psoriasis may be passed down from parents to their children (inherited). White (Caucasian) people who carry a certain gene have a much greater risk of developing psoriasis.³ About one-third of people who have psoriasis have one or more family members with the condition.¹

Other factors that can contribute to the development of psoriasis include:

• Cold climates. Cold weather makes symptoms worse.
• Emotional or physical stress. Stress may cause psoriasis to appear suddenly or make symptoms worse (although this has not been proven in studies).
• Infection. Infections such as strep throat can cause psoriasis to appear suddenly, especially in children.
• Skin injuries. An injury to the skin can cause psoriasis patches to form anywhere on the body, including the site of the injury. This includes injuries to your nails or nearby skin while trimming your nails.
• Certain medicines. Certain medicines, including some heart medicines (beta-blockers) or medicines to treat mental illness (for example, lithium), may make psoriasis symptoms worse.
• Smoking. Smoking may make you more likely to get psoriasis and make the symptoms more severe. Smoking may also make your symptoms last longer.^{4, 5}
• Weight gain in women. A large study has shown that women who gain weight throughout adult life are more likely to develop psoriasis.⁶