Which of the following factors is the primary etiological factor in psoriasis?

Explanation: Psoriasis has a strong genetic component, and individuals with a family history of the condition are more likely to develop it. Specific genetic factors are involved in the immune response and skin cell growth regulation, leading to psoriasis.

Incorrect choices: b. While exposure to certain chemicals and irritants can exacerbate psoriasis symptoms, they are not the primary factor contributing to its development.

c. Psoriasis is not caused by a bacterial infection. It is a non-infectious inflammatory skin disorder.

d. Sun exposure can affect psoriasis, but it is not the primary factor contributing to its development. In some cases, moderate sunlight exposure may even improve psoriasis symptoms.

Explanation: Psoriasis is an autoimmune skin disorder where the immune system mistakenly attacks healthy skin cells, leading to the rapid buildup of skin cells and the formation of red, scaly patches on the skin's surface.

Incorrect choices: a. A contagious bacterial skin infection - Psoriasis is not caused by bacteria, and it is not contagious.

c. A fungal infection causing itching and rash - Psoriasis is not caused by a fungus; it is an autoimmune condition.

d. A viral skin condition resulting in fluid-filled blisters - Psoriasis does not result in fluid-filled blisters; it presents as red, scaly patches instead.