What is psoriasis?
The cause of this disease is an alteration of the immune system that causes an inflammatory chain reaction in the body’s defence mechanisms that results in excessive production of skin cells.
It appears as pinky-red patches covered with silvery-white scaly skin. It mostly appears on elbows, knees, the lower back and the scalp, but can also occur on other parts of the body.
Up to a third of people with psoriasis may go on to develop joint problems, or psoriatic arthritis, characterized by inflammation of the joints. This is generally intermittent and asymmetric and mainly occurs in the fingers, toes and lower spine.
It most commonly appears as skin lesions, which can sometimes itch or become sore, especially if the skin cracks or is broken. There are different types of psoriasis:
- Plaque psoriasis. This is typified by red lesions patches covered with scaly silvery-white dead skin cells. It is the most common type.
- Inverse psoriasis. Patches show up in the folds of the body such as the armpit, the groin, under the breasts or between the buttocks.
- Guttate psoriasis: These are small patches and are spread irregularly over the entire body. They normally appear in children and young people, especially after an episodic pharyngotonsillitis infection.
- Erythrodermic psoriasis. This is a very intense reddening of the skin that covers most of the body. It is very rare but can be serious and require admission to hospital.
- Pustular psoriasis. This is a rare condition and where it covers the whole body it may also be severe and require admission to hospital. It is typified by non-infectious white pustules surrounded by red patches.
Aside from skin lesions, people with psoriasis may develop psoriatic arthritis, which occurs as pain, heat and reddening around the joint and being unable to move the joint. In its advanced stages, there may be deformities, pain in the heels and back pain.
Who does psoriasis affect?
It affects 2-3% of the world population. 10-30% of sufferers develop arthritis, which can occur at any time, although it is more likely between 30-50 years old.
Diagnosis is by observation of the lesions and the areas around them. Specialists may sometimes perform a skin biopsy to confirm diagnosis and to rule out other conditions that may appear similar or have the same symptoms.
There are currently different treatments to alleviate symptoms and signs, and which also cure the skin lesions in most cases. The dermatology specialist will decide the most suitable treatment for each patient, depending on the type of psoriasis, where it is on the body, the severity, and type of patient.
There are three types of treatment:
- Topical. Creams, shampoos and lotions applied directly to the skin.
- Phototherapy. Treatment with ultraviolet A light (UVA rays) or ultraviolet B light (UVB rays), usually administered 2-3 times a week for 2-3 months.
- Systemic or generalised. Medication taken orally (pills) or injected. Treatment must be strictly monitored through blood tests in order to control possible side effects