Psoriasis
Summary/Definition
Psoriasis is a recurrent chronic skin disease characterized by the formation of erythematous papules and plaques on the skin, covered with silvery-white scales of varying size and with well-defined borders. The disease has a wavy character and there is a clear demarcation between the affected areas and healthy skin. Psoriasis can occur in a variety of clinical forms, including scales, plaques, pustules, exfoliative (erythrodermic) psoriasis and psoriatic arthritis. Factors that are thought to aggravate or make psoriasis worse include skin trauma, infections, stress, taking certain medications, exposure to cold and dry climates, dry skin, etc. Psoriasis gets better when steroids are taken to relieve symptoms but gets worse when treatment is stopped. The exact cause of psoriasis is unknown, but it is thought to be caused by genetic factors, the environment and triggers, and immunological aspects.
Symptoms
Psoriasis usually develops symmetrically and is most common on the extensor surfaces of the extremities, such as the elbows, knees, sacrum and scalp. At first, small papules resembling grains appear, which gradually increase in size until they reach the size of a walnut or even a hen’s egg. Over time, small new patches appear around the main patches, which gradually coalesce to form larger plaques. The surface of these plaques is covered with white scales. When these scales are removed, petechiae (pinpoint bleeding) usually occur, which is one of the specific symptoms of psoriasis. Pustular psoriasis, characterized by the formation of pustules (vesicles) on the skin, is one of the rarer forms of the disease. Nail lesions are also seen in 30-50% of people with psoriasis and may include indented nails, peeling, thickening, hyperkeratosis under the nail and yellowish-brown spots under the nail. Depending on the clinical form, psoriasis may be patchy, plaque-like, intertriginous (psoriasis in skin folds), scalelike, pustular or exfoliative.
Diagnostics
Typical psoriasis lesions can be diagnosed based on skin changes alone. However, if there are no typical skin lesions, a skin biopsy may be carried out to confirm the diagnosis.
Treatment and course of the disease
Psoriasis can be treated using a variety of methods, including topical therapy, phototherapy, systemic therapy and biologic medications. The choice of a particular method or combination of methods depends on the characteristics of each patient. To minimize side effects and ensure the effectiveness of treatment, it is recommended to use a cyclical approach, where different treatments alternate periodically, or a ‘cascade’ approach, where treatment is given in stages. Medications include topical ointments, immunomodulators such as cyclosporine, systemic vitamin A derivatives (e.g., retinoids) and biologics that suppress the excessive immune response in psoriasis. In addition to medications, non-drug treatments include phototherapy using single wavelength (narrow band) ultraviolet B (UVB) light.
