[Medical Q&A] I have psoriasis. Will it be contagious to my family?

Planner: Chinese Medical Association

Reviewer: Li Chengxu, Chief Physician of China-Japan Friendship Hospital

Psoriasis is not contagious, so the patient's family is safe.

Psoriasis is an inflammatory skin disease caused by autoimmune disorders. It is not caused by direct infection by pathogens such as viruses and bacteria, so it is not contagious. But from a genetic point of view, family members have to be cautious. Data show that 31.26% of psoriasis patients have a family history. When one parent has psoriasis, the incidence rate of their children is about 20%; when both parents have psoriasis, the incidence rate of their children will be higher, reaching 65%. If there are twin brothers and sisters, the probability of identical twins developing the disease is 65% to 72%, while the probability of fraternal twins developing the disease is slightly lower, only 15% to 30%.

However, heredity is not the only cause of psoriasis. In addition to heredity, factors such as lifestyle habits, external environment, and abnormal immune function may also cause the disease.

(1) Lifestyle habits: Smoking, secondhand smoke or heavy drinking will not only affect the skin barrier function, but also reduce immunity, thereby increasing the risk of disease.

(2) External environment: In the north where the climate is dry, the prevalence of psoriasis is higher. This may be because the dry environment can easily damage the skin barrier function, thus inducing psoriasis.

(3) Abnormal immune function: If you are in a state of high tension or high-intensity work for a long time, the mental pressure will be too great, and the human body will be in a state of stress, which will affect the body's immune function. Among them, the immune process initiated by T lymphocytes is the key to the occurrence and aggravation of psoriasis.