Red spots on the skin. The spots in psoriasis have several modifications and their corresponding symptoms. With the most common vulgar psoriasis, the spots look like plaques that first appear as flat, clearly delimited erythematous maculae – round-oval, diameter less than 1 cm – or dense red papules that just rise above the healthy skin. Usually, they appear on such parts of the body like elbows, lower back, knees and also on the head (on the scalp), and then on any other areas of the body, but almost always symmetrically.