Psoriasis is a chronic immune mediated relapsing disease of skin and there are several different clinical types of psoriasis. Different types of psoriasis may show different clinical manifestations/symptoms. In general psoriasis is the types of psoriasis are non-pustular, pustular and other types of psoriasis.
This is further subdivided into Psoriasis vulgaris (also known as chronic stationary psoriasis and plaque-like psoriasis) and erythrodermic psoriasis.
This is the most common form of psoriasis, which accounts for up to 90% of individuals with psoriasis. In this form of psoriasis there plaque formation occurs, which appears as raised areas of inflamed skin, which have silver color scales.
This form of psoriasis causes widespread inflammation and exfoliation of the skin, which can cover large area of body surface. There may be itching, pain and swelling in the area of the skin where inflammation and exfoliation occurs. Sometimes erythrodermic psoriasis may occur due to exacerbation of Psoriasis vulgaris, especially upon abrupt withdrawal of systemic treatment. Rarely this form of psoriasis (erythrodermic psoriasis) can cause death, as there is disruption of temperature regulation of the body due to extreme inflammation and exfoliation of skin, which can not function normally.
The skin in pustular psoriasis shows multiple raised bumps that are filled with noninfectious pus (known as pustules). The area surrounding the pustules is red and tender. This pustules commonly occurs hands and feet, but can be generalized and occur randomly at any part of the skin. There are several varieties of pustular psoriasis, such as generalized pustular psoriasis (also known as pustular psoriasis of von Zumbusch), palmoplantar pustulosis, annular pustular psoriasis, impetigo herpetiformis etc.
Other types of psoriasis:
There are several other types of less common psoriasis.
- Drug induced psoriasis.
- Napkin psoriasis.
- Inverse psoriasis: may occur in skin folds, such as genitals, inframammary folds (under the breasts), armpits, abdominal folds in obese individuals etc. This type of psoriasis may be infected by fungus and may get irritated by friction and sweating.
- Nail psoriasis: occurs in nails (finger nails and toe nails) and produce changes in the appearance of finger and toe nails such as discoloration of under the nail plate, pitting of the nails, thickening of the skin under the nail, and the loosening/crumbling of affected nails.
- Psoriatic arthritis: as the name suggest, it affect and cause inflammation of joints and connective tissues. Most commonly joints of the fingers and toes are affected and cause swelling of fingers. Sometimes hips, knees and spine may be involved. Approximately 10% of all psoriasis patients have joints and connective tissues involvement (psoriatic arthritis).
- Guttate psoriasis: the skin lesions (scales) are red or pink, teardrop-shaped and large in number and commonly occur in the trunk, but can also occur in the limbs and scalp.