Psoriasis (Gr. Psora = shell) is a chronic inflammatory skin disease characterized by the appearance of sharply limited red skin plaques covered with dry silvery-white scales. Disease often affects the skin of scalp and nails and in some patients joints in form of psoriatic arthritis. Psoriasis affects about 1-3% of general population with highest incidence in Scandinavian countries (3) and lowest in Native North America (0.5). In Croatia psoriasis affects about 80,000 people. Psoriasis can occur at any age, but almost in 50% of patients condition occurs under 25 years of age.
The specific cause of psoriasis is not fully known, but it is assumed that the disease is result of interaction of inherited genetic factors and various environmental factors. Today it is considered that inheritance of condition is polygenic meaning that a combination of several genes located on different chromosomes are responsible for psoriasis development. Inflammatory process in psoriasis is triggered by immune factors and T cells involved in the immune response.
For condition to manifest itself in genetically susceptible individuals a various external factors (trauma, bacterial and viral infections) or internal (stress, pregnancy, endocrine, or metabolic disorders) are needed. Mental stress often triggers the first appearance of psoriasis and in almost 30-40% patients worsens the clinical course of the disease. Throat streptococcal infection in children and youth usually causes the appearance of a special form of psoriasis called droplet psoriasis, which is characterized by the appearance of small psoriasis fallouts.
Sunlight usually improves clinical symptoms and skin changes are considerably less pronounced in summer months. Certain habits such as smoking and alcohol can worsen the course of psoriasis.
Treatment of psoriasis
In treatment of psoriasis local and / or systemic medication can be used. Treatment depends on factors such as patient age, clinical form of psoriasis, localization and extent of psoriatic changes, as well as the condition of the patient. In most patients, especially those with severe range of skin changes and those associated with arthritis an interdisciplinary approach is needed.