Psoriasis types

Plaque psoriasis, also known as psoriasis vulgaris, known as well as psoriasis vulgaris, is the most common type of psoriasis, affecting about 90% of people with psoriasis. It is characterized by red patches covered with white or silver flaky scales, although the scales may be less visible after bathing or moisturizing.

These plaques vary in size and can appear on the elbows, knees, scalp, and lower back, but they may occur anywhere on the skin. Symptoms range from asymptomatic to itching, burning, pain or bleeding.

Guttate psoriasis (from latin guttae, which means “drop/droplet”) is a type of psoriasis that appears suddenly with many small, droplet-like lesions. These lesions usually measure between 2 and 15 mm in diameter. They are reddish in color and covered by flaky skin layers, thinner than those in plaque psoriasis. This form typically affects the trunk and the upper parts of the arms and legs, but it can also appear on the scalp, hands, feet, and nails. Some people experience itching, while others have no discomfort.

Guttate psoriasis is the second most common after plaque psoriasis and occurs most often in children and adolescents. In most cases, guttate psoriasis clears on its own within a few weeks or months, but it can return intermittently or progress to plaque psoriasis. 

Inverse psoriasis appears as very red, smooth and shiny lesions in body folds, such as behind the knees, under the arms, in the groin, or under the breasts. Inverse psoriasis often occurs together with other types of psoriasis. 

Pustular psoriasis causes small white or yellow blisters filled with non-infectious fluid surrounded by red, scaly skin. These blisters can group together to form a larger blister.

This type is rare and mainly affects adults. It can be triggered by certain medications, abruptly interrupting a treatment, infections, or pregnancy. Depending on extension, pustular psoriasis can be generalized or localized.

Erythrodermic psoriasis is the most severe form of psoriasis, but also the least frequent. It affects less than 3% of people with psoriasis. It causes almost all the skin to turn red and peel off in sheaths, leading to intense itching and pain. The most frequent triggers are medications, infections, and abrupt withdrawal from systemic psoriasis treatment.