Fast Five Quiz: Plaque Psoriasis Presentation and Diagnosis

Chris G. Adigun, MD


July 09, 2021

The physical examination of a patient with plaque psoriasis may reveal symmetrical lesions on the scalp, trunk, buttocks, and limbs as well as the extensor surfaces of the knees, elbows, and genitals. However, in some cases, plaque psoriasis may present as well-demarcated round to oval-shaped lesions ranging in size from 1 cm to several centimeters.

Widespread erythema covering nearly the entire body with variable amounts of scaling may be seen with erythrodermic psoriasis, not plaque psoriasis, and is considered a life-threatening emergency, as these patients are at risk for hemodynamic instability. The development of erythrodermic psoriasis can be triggered by the withdrawal of systemic corticosteroid treatment. Other precipitating factors may include erroneous topical therapy and chloroquine or lithium administration. Clinical cues for psoriatic erythroderma include a pre-existing history of plaque or pustular psoriasis, nail psoriasis, psoriatic arthritis, and the sparing of the central face. Skin biopsy for histologic examination is needed for differential diagnosis.

Dewdrop–shaped, salmon-colored papules with fine scale are characteristic of guttate psoriasis, not plaque psoriasis.

Learn more about the signs and symptoms of plaque psoriasis.


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