Plaque psoriasis (psoriasis vulgaris)
This is the most common form of psoriasis. It generally appears in the second or third decade of life in the form of small isolated lesions that then grow and form large spots mainly on the elbows, knees, sacral area and on the buttock crease.
Characterized by the onset of red spots that then flake off. This form of psoriasis affects mainly the trunk - though it rarely involves the face and scalp - and causes general malaise and pain in the joints.
It may be localised or generalised, with different levels of severity. It is characterised by large erythematous-desquamative patches – mainly in the trunk – that are surrounded by pus-filled pustules.
The most severe form, though fortunately very rare. It is often linked to a previous form of psoriasis and triggered by many factors, such as atopic dermatitis associated with wrong therapies, allergic-toxic reactions or important psychological traumas
Mirror-like version of plaque psoriasis, generally located around the groin, armpits, bellybutton and under the breasts. The patches are very inflamed with little or even no flaking.
Variables of the main forms
Psoriasis of the scalp
The scalp is generally hit by psoriasis vulgaris; it is seldom the only area involved. It has the shape of an erythematous rim with sharp margins, covered with white-dry silvery scales - located at the hairline - which also affects the forehead and ears.
It is quite rare and it mainly involves the nails. In psoriatic arthritis patients, it is often the only form of psoriasis that can be seen on their skin. It may show lines going all along or across the nail plate.
The patches are located on hands and feet and are not always symmetrical. The skin is dehydrated with whitish scales with a laminar aspect that tend to rise leaving parts of the skin uncovered. In some cases, it may worsen and become associated with severe forms of arthritis, leading to psoriatic arthritis.