Common disease which affects the skin. The skin is often inflamed, red, and covered in dark patches or scales. The areas affected can cause physical discomfort and social embarassment1.
Psoriasis is a fairly common disease. It occurs in about 2% in Caucasian populations and less frequently in Negroid and Asian people. The disease has not been observed in Native American people.
Men and women are considered to be equally affected by psoriasis. The condition arises in people within the 10 to 30 year old category, but can also present in young children and during old age.
Causes Of The Disease
The exact cause is not known. However the condition is thought to be hereditary. (Passed down from one generation to the next). The severity of psoriasis in a person may vary. However factors including emotional stress, skin damage and physical illness may contribute to the presenting condition. Environmental factors (eg: Infection from bacteria) and the reaction of the body to drugs have also been associated with this condition.
Varying factors within the body may also be responsible for Psoriasis. The excessive presence of circulating hormones (for example the female sex hormones Oestrogen and Progesterone) may also be responsible for aggravating the condition2.
New skin cells are produced at about 10 times the normal rate to that of normal. As a result the live cells accumulate and form characteristic thickened patches covered with dead flaking skin. The result is very un-aesthetic (Un-attractive).
The eruption of the skin can be associated with painful swelling and stiffness of the joints. This stiffness can be very disabling.
Cardio-vascular disease, Digestive problems and a reduced blood cell count (resulting in a decreased immune response) are thought to be associated with this disease3.
Classifying The Disease
Psoriasis may present as different types.These include :
- Discoid (Plaque ) Psoriasis - Most common form. Patches appear on the trunk and limbs. The elbows and knees are particularly affected. The scalp may also be involved. In addition the nails may become pitted, thickened or may separate from the nail beds.
- Guitate Psoriasis - Occurs most frequently in children. Numerous small patches appear on the skin and develop rapidly over a wide area. This disease is often preceded by a sore throat.
- Pustular Psoriasis - Characterised by small pustules (swellings) which may occur all over the body or be confined to local areas.
A combination of histological (cell studies) and pathological (study of the disease process) is needed to arrive at the diagnosis of Psoriasis4. Often a biopsy (sample) of skin from an affected area is removed (painlessly) and analysed under a microscope. With the use of various chemicals and techniques the dia