The genetics of psoriasis is complex. Research indicates that it is abnormalities in two or three genes that usually cause psoriasis. A trigger, usually environmental, is also needed to set off the disease. Trauma to the skin is a common trigger and can include grazes, mechanical friction, and thermal or sun burns. Infection is another trigger, with streptococcal sore throat often precipitating the onset of childhood psoriasis.
Stress can exacerbate psoriasis, as can heavy drinking and smoking.
Cold weather and the dryness caused by central heating often worsens the condition. Treatment strategies Treatment aims to induce remission, prevent recurrence, relieve symptoms and improve function. A spectrum of therapies is required as the disease affects each patient differently and there can be a variable response to any particular agent. Newer therapies are getting patients away from the cumbersome coal tar and dithranol. Psoriasis treatments tend to be divided into topical and systemic therapies.