Papulosquamous skin disorders: Clinical

Papulosquamous disorders are a heterogeneous group of disorders whose etiology primarily is unknown, that present with both red papules and scaling.

The major entities in this group include psoriasis, parapsoriasis, lichen planus, pityriasis rosea, and seborrheic dermatitis.

Diagnosis is most often clinical, taking into account the location and distribution of the papulosquamous skin lesions. Only a few cases may require further investigation with skin biopsy to confirm diagnosis and choose the appropriate treatment.

Psoriasis is a chronic and complex immune-mediated disease that causes skin inflammation, presenting as well-demarcated, erythematous plaques with silver scales that can be incredibly pruritic or itchy.

For some individuals, having psoriasis may have psychosocial effects with a significant negative impact on the quality of life.

The causes of psoriasis aren’t clear but there’s definitely a genetic component and environmental triggers like trauma, stress, or smoking.

Symptoms of psoriasis can vary, and there are a few subtypes.

Plaque psoriasis is the most common. It appears as flattened areas of epidermal elevation that are inflamed and red or salmon-colored, from the underlying dilated blood vessels, and are topped with white-silvery scales.

Plaques are typically itchy and found on the scalp and in tensor regions, like the elbows, groin, lower back, and knees.

Guttate psoriasis appears as small, red, individual spots on the trunk and limbs.

This subset usually starts in childhood, and is sometimes triggered by an infection, like strep throat.

Inverse psoriasis appears as smooth and shiny red lesions that lack scales and typically form within skin folds like in the genital region, under arms or under the breasts.

Pustular psoriasis appears as areas of red skin with small, white elevations of cloudy pus, formed from dead immune cells. They are usually tender and form on the hands and feet.

Erythrodermic psoriasis is usually the most severe subset, and appears as fire-red scales that can cover a large area of the skin. They are often extremely itchy and painful and fall off in large sheets.