Different forms of psoriasis
Psoriasis may be a difficult disease to treat, depending on the form of the disease from which the patient suffers. Symptoms are highly individual in affected patients since the triggers can vary significantly .

Plaque psoriasis is the most common form of psoriasis and is characterised by its spotted scaly appearance. This form of the disease afflicts 80% of all individuals who suffer from psoriasis. Plaque psoriasis is characterised by round lesions 3 to 10 cm in size and usually arise on the knees, elbows and lower back. Mild itching may occur when the lesions are new. This type of psoriasis often occurs in existing wounds or scars. Plaque psoriasis is usually symmetrical with corresponding lesions found on both sides of the body. This tendency is commonly seen on the knees and elbows. One sign of plaque psoriasis is that the lesions itch or produce a burning sensation. Lesions begin as small red spots that grow larger into scaly, thickened red patches.

Guttate psoriasis is characterised by teardrop-shaped lesions that suddenly appear all over the body. They are 2-5 mm in size and usually first appear on the arms and legs. The teardrop-shaped psoriasis usually arise at an early age or during puberty among individuals who suffer from a streptococcal throat infection (strep throat). Guttate psoriasis is the second most common form and affects about 10% of psoriasis patients. In many cases the symptoms completely disappear after a few months, only to reappear at a later stage in life as plaque psoriasis. Guttate psoriasis usually breaks out a few days after the beginning of a strep infection, but other infections can also be contributing factors to the outbreak of this form of psoriasis.

Inverse psoriasis is characterised by well-defined red lesions that are shiny and smooth. Scaling in inverse psoriasis is rare, as is this form of the disease. Inverse psoriasis occurs in skin folds and is also known as flexural psoriasis. It is commonly found in the groin, armpits, navel, and genitals, as well as under the breasts and between the buttocks. The skin where inverse psoriasis develops on is highly sensitive and easily irritated by chafing and sweating. Overweight individuals tend to be affected by inverse psoriasis, and they also often suffer from another form of psoriasis.

Scalp psoriasis is a type of psoriasis that may occur in conjunction with other types of psoriasis, usually plaque psoriasis or guttate psoriasis. 50 % of all individuals who suffer from one form of psoriasis also have scalp psoriasis. This form of psoriasis can be found on the neck, ears or around the hairline on the forehead. For some people, scalp psoriasis can appear as mildly reddened spots, while others have itchy, thickened areas with dandruff. Sometimes it can be difficult to distinguish between psoriasis and dandruff. This form of psoriasis typically causes more itching than other forms of the disease.

Nail psoriasis affect about 25-50% of all individuals affected by psoriasis. For some individuals this form of psoriasis presents itself as single punctuate indentations (pitting), while others experience dark discolouration or thickening of the nail. Nail psoriasis can be compared with a severe nail fungus infection.

Pustular psoriasis is a more severe form of psoriasis. It can be local or generalised, affecting about 5% of all psoriasis patients. This form of psoriasis usually only occurs among adults and is characterised by pus-filled yellowish blisters. The local form of pustular psoriasis arises in specific areas of the body such as toes, palms, soles and fingers, causing swelling, redness and blistering.

The most common form of pustular psoriasis is Palmoplantar Pustulosis (PPP), which usually exclusively affects women. Also, this form of the disease almost exclusively affects smokers (95% of all individuals with PPP) and is usually found on the palms and/or soles. PPP causes redness, tenderness and swelling with pus-filled blisters. For some individuals the blisters can be painful and affect the ability to use the hands in a normal way or to walk on the soles. In the first stage, the blisters are about 1-10 mm in size and yellow, but subsequently the appearance changes to a brown surface that starts to peel after 1-2 weeks.

Generalised pustular psoriasis is a severe but rare form of psoriasis characterised by formation of dense blisters that cause redness and tenderness of the skin. Other symptoms include fever, fatigue and exhaustion, as well as muscle weakness and loss of appetite. It is also common for patients to feel chilled and to have a rapid pulse. Individuals who suffer from generalised pustular psoriasis have to be hospitalised, especially older individuals, since the condition may be life-threatening. Factors that can trigger pustular psoriasis include sunburn, infections or medicine.

Erythrodermic psoriasis is the rarest form of psoriasis, affecting only 1% of all psoriasis patients. Unlike other forms, it is painful and extremely itchy. The skin becomes very red, fluid-filled, swollen and extremely flaky and scaly. The symptoms can be similar to those of a burn. Erythrodermic psoriasis can be caused by a trigger such as infection, alcoholism, some medications, mental stress, and discontinuation of a psoriasis treatment. The ability of the skin to build a barrier for fluid- and heat loss is affected amongst patients with erythrodermic psoriasis. The skin barrier protecting the body against bacteria is also destroyed or severely impaired. Because of these factors, this form of psoriasis is life-threatening and patients are therefore hospitalised after diagnosis for hydration and in some cases to stabilise body temperature.

Site updated 2016-01-12