What Is Psoriasis?

Psoriasis is a term that describes a condition of the skin of two main varieties, pustular and nonpustular, along with several less common varieties. The most commonly found form of psoriasis is of the nonpustular variety referred to as psoriasis vulgaris (chronic stationary psoriasis, plaque-like psoriasis) (L40.0).

Psoriasis vulgaris affects 80-90 percent or persons suffering from psoriasis, it’s characterized by inflammation, raised areas of skin, covered by white to silvery white “scales”, these inflamed areas are called plaque.

Another form of nonpustular psoriasis is referred to as psoriasis erythroderma (L40.85). This form of psoriasis is characterized by inflammation and exfoliation of the skin over a large area of the body; these symptoms are often accompanied by severe itching and pain. This form of psoriasis is often the result of an exacerbation of unstable plaque psoriasis; this is often brought on after the abrupt withdrawal of systemic treatment. Erythroderma psoriasis can be fatal, as the extreme inflammation and exfoliation can disrupt the body’s ability to regulate temperature and for the skin to perform barrier function, making the sufferer prone to infection.

Then there are the Pustular psoriasis (L40.1-3, L40.82). This type of psoriasis is charaterized by raised “bumps” or pustules that contain non-infectious pus. The areas of skin surrounding these pustules are sensitive, red and inflamed. Pustular psoriasis can affect any part of the body but is more often found on the hands and feet. Pustilar psoriasis is broken down into several sub-categories:

  • Generalized pustular psoriasis (pustular psoriasis of von Zumbusch)
  • Pustulosis palmaris et plantaris (persistent palmoplantar pustulosis, pustular psoriasis of the Barber type, pustular psoriasis of the extremities)
  • Annular pustular psoriasis
  • Acrodermatitis continua
  • Impetigo herpetiformis

But wait theres more” ¦
There are more varieties of psoriasis still;

  • Drug induced psoriasis, which may occur as an adverse reaction to certain types of medications.
  • Inverse psoriasis (flexural psoriasis, inverse psoriasis)(L40.83-4) this type of psoriasis appears as smooth inflamed patches of skin that occurs in skin folds, particularly around the genitals (between the thigh and groin), the armpits, under an overweight abdomen (panniculus), and under the breasts (inframammary fold). This type of psoriasis is aggravated by friction and sweat, and is vulnerable to fungal infections.
  • Napkin psoriasis
  • Seborrheic-like psoriasis
  • Guttate psoriasis (L40.4), characterized by numerous small, scaly, red or pink, teardrop-shaped lesions, this form of psoriasis may occur over large areas of the body, primarily the torso, but also may occur on the limbs and scalp. Guttate psoriasis may often occur after a streptococcal infection, typically streptococcal pharyngitis.
  • Nail psoriasis (L40.86) affects the toenails and finger nails and may be identified by changes in their appearance. These changes include discoloring under the nail plate, pitting of the nails, lines going across the nails, thickening of the skin under the nail, and the loosening (onycholysis) and crumbling of the nail.
  • Psoriatic arthritis (L40.5) this form of psoriasis is characterized by joint and connective tissue inflammation. Psoriatic arthritis can affect any joint, but is most commonly found in the joints of the fingers and toes. This may result in a sausage-shaped swelling of the fingers and toes known as dactylitis. Psoriatic arthritis has also been found to affect the hips, knees and spine (spondylitis), 10-15% of people who have psoriasis also have psoriatic arthritis.

And other less common forms of psoriasisis that affect parts of the mouth are believed to be oral manifestations of psoriasis that are histologically identical to cutaneous psoriasis lesions. Oral forms of psoriasis are most often found among persons suffering other forms of psoriasis, although these conditions are also common in the non-psoriatic population and affect 1% to 2.5% of the general population.



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