A chronic, hereditary, recurrent dermatosis marked by discrete vivid red macules, papules or plaques covered with silvery lamellated scales.
causes, incidence and risk factors:
Psoriasis is very common, approximately 3 million Americans affected (or about 8 out of 10,000 people). It can appear suddenly or gradually. It may affect any age but most commonly begins between 15 to 35 years old. It occurs most frequently in Caucasians. Psoriasis is characterized by frequent episodes of recurrences and remissions.
Psoriasis by a foreign agent caused by Psoriasis vulgaris. Improper food habits, unhygenic living atmoshphere and it is mainly idiopathic.