Psoriasis is an autoimmune skin allergy that results in skin redness with flakes, silver-white patches, irritation, etc. It is a non-contagious. It is basically allergic manifestation of skin that develops when the immune system triggers the excessive growth of skin cells. In case of psoriasis, there is an abnormal production of immune cells called T cells in the skin. These T cells are responsible for regulating the immune system response to foreign invaders such as bacteria or viruses. The abnormal production of these cells leads to rapid growth of skin cells leading to inflammation and flaking of the skin.
Causes:
Well, until now, there are no known causes of psoriasis but some combined factors are recognized to cause psoriasis such as genetic predisposition, environmental factor, viral or bacterial infection, etc. In most of the cases, it has been found that patients reports a family history of psoriasis. It runs down within a family. Over-exposure or limited exposure to sunlight may also develop psoriasis. Some medicines may also result in psoriasis.
Types of Psoriasis:
Psoriasis can be classified as various types depending on its symptoms:
1) Plaque Psoriasis
2) Guttate Psoriasis
3) Pustular Psoriasis
4) Inverse Psoriasis
5) Erythrodermic Psoriasis
Plaque Psoriasis: It is the most common type of psoriasis. The affected area turns red, covered with silvery scales and is inflamed. Patches with red skin are formed that generally results in itching. The most common areas where plaque psoriasis occurs are elbows, knees, scalp, trunk, etc.
Guttate Psoriasis: This type of psoriasis is characterized by formation of teardrop-shaped lesions with red and scaly skin. These lesions affect the large areas of the body such as a trunk. Scalp and limbs might also develop these lesions.
Pustular Psoriasis: Pustular psoriasis results in outward manifestation filled with noninfectious pus or pustules. The skin around the raised bumps generally remains red and tender. These pustules first appear on localized areas such as hands and feet but may spread to other body parts.
Inverse Psoriasis: Inverse psoriasis occurs generally in skin folds and appears as smooth inflamed patches of skin. These patches are vulnerable to fungus infections and gets worse by sweat and friction. The major body parts where these patches can appear are genitals, armpits, etc.
Erythrodermic Psoriasis: Erythrodermic psoriasis or Psoriatic Erythroderma is severe inflammation and exfoliation of the skin over the major body parts. It accompanies itching, swelling or pain.
How Psoriasis affects other body parts?
Dandruff: It is the initial stage of psoriasis, and it results in formation of thick scales on the scalp over a long period of time.
Nail changes: Most of the patients of psoriasis develop psoriatic changes in finger/toe nails. Nail changes are quite evident in around half of the case reporting psoriasis. Some common conditions are redness of the skin around the nails, deep pitting, appearance of white spots under the nail plate, or complete loss of nails.
Changes in muscles and joints:Psoriasis patients may develop joints and muscle inflammation with stiffness that is also known as Psoriatic Arthritis. It may result in asymmetrical involvement of joints.
Mucous membrane: There may occur white patches over tongue and anogenital areas.