Psoriasis

Many doctors believe that psoriasis may be passed down from parents to their children (inherited). This is because certain Reference genes Opens New Window are found in families who are affected by psoriasis.^{Reference 2} About one-third of people who have psoriasis have one or more family members with the condition.^{Reference 1}

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

• Emotional or physical stress. Stress may cause psoriasis to appear suddenly or make symptoms worse (although this has not been proved in studies).
• Infection. Infections such as Reference strep throat Opens New Window 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.
• Smoking. Smoking may make you more likely to get psoriasis and make the symptoms more severe.^{Reference 3}

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