Psoriasis is a disease of the immune system that affects the skin. The disease is long-lasting and appears as abnormal patches on the skin. Psoriasis is associated with stress, arthritis, type 2 diabetes, and cardiovascular diseases. Psoriasis is non-contagious.

Psoriasis shows up as red, scaly, dry and itchy patches on different parts of the body based the type of psoriasis is present. The disease can be localized to a very small part of the body or can spread across the entire body. There are many different types of psoriasis that affect different parts of the body. Some of the more common forms are:

• Plaque psoriasis
  Usually, the body takes about 28 to 30 days to shed old skin cells and replace them with new skin cells. Psoriasis sets in when the immune system overreacts and speeds up the production of new cells. These new cells are pushed to the surface of the skin in about 3 to 4 days. The body cannot shed skin cells at this fast pace and these skin cells pile up, as the new skin cells push up from beneath the outer skin layer. These piled up skin cells form scaly patches on the skin, known as plaques. Plaque psoriasis is also called by the names chronic stationary psoriasis and psoriasis vulgaris. This form of psoriasis is the most common form found in 85% to 90% of all psoriasis cases.
• Guttate psoriasis
  Small, scaly, red or pink lesions in large numbers are the characteristics of guttate psoriasis. These lesions or papules are droplet-shaped and are approximately 1-10 mm in diameter, and occur mostly on the scalp, arms, trunk, and legs. Guttate psoriasis is seen most commonly in people who are less than 30 years old. Guttate psoriasis is caused by a streptococcal infection, and occurs as a sudden eruption of skin lesions, within three weeks of the infection.
• Pustular psoriasis
  This form of psoriasis has white pustules (noninfectious pus-filled bumps) surrounded by red skin blotches. These pustules are itchy, flaky, and have scales. Pustular psoriasis occurs mainly on the palms of the hands, on the fingers and toes, and on the soles of the feet. Pustular psoriasis has a tendency to run in families and affects adults, and very rarely on children. Pustular psoriasis can form on its own or can erupt if the person has plaque psoriasis.
• Inverse psoriasis
  Also called flexural psoriasis or intertriginous psoriasis occurs in body folds such as armpits, under the breasts and in the groin and buttock areas. These are susceptible to irritation, rubbing and sweat. Other complications that can arise are fungal, bacterial and yeast infections. Unlike other forms or psoriasis, there are no scales as the environment is usually moist.
• Mouth psoriasis
  Mouth or oral psoriasis is a very rare form and is difficult to diagnose. This form manifests as spots in different parts of the mouth, but most commonly on the inside of the cheeks. This can be accompanied by sores, peeling skin on the gums, pustules, change in taste, and pain while eating spicy foods.
• Nail psoriasis
  Nail psoriasis alters the way fingernails and toenails look. Nails may change color or shape, develop pinprick holes or become thick. The affected nail can have debris build up under it and can get separated from the nail bed. Nail psoriasis can be mistaken for nail fungus or onychomycosis, an infection caused by fungi.
• Seborrheic-like psoriasis
  This form of psoriasis is also called sebopsoriasis or seborrhiasis. It is characterized by seborrheic dermatitis overlapping psoriasis. The scales are more yellowish and greasy, and less silvery than scales of other psoriasis forms.
• Erythrodermic psoriasis
  This is a very uncommon form and is characterized by a red, peeling rash that covers the entire body.

There is no cure for psoriasis and the best option is to treat the symptoms.