Chronic Plaque Psoriasis
The most common presentation of psoriasis is the chronic plaque form. This form typically involves extensor extremities (elbows and knees), scalp, and sacrum. Red, sharply defined, scaling papules that coalesce to form stable round to oval plaques. Usually the palms, soles, and face are spared.
The deep rich red color is a characteristic feature that remains constant. The scale is adherent, silvery white and reveals point bleeding when removed. This is known as Auspitz sign.
Individual plaques vary from thick and infiltrated to thin. Similarly the overlying scale may be thin and translucent to extremely dense, white and yellow-stain from serum. Thick scale may accumulate on the scalp.