The difference between seborrheic dermatitis and psoriasis

Seborrheic dermatitis is a common chronic inflammatory recurrent skin disease in clinical practice, mainly occurring on the head, face, chest and back. At present, the etiology is not very clear, which may be related to Malassezia colonization, skin barrier function damage, susceptibility, lipid increase, etc. The main clinical manifestation is small chaff oily desquamation based on unclear erythema, hair loss, and generally no fascicular hair. Psoriasis is a chronic inflammatory recurrent systemic skin disease affected by environment and heredity. The typical clinical manifestation is silvery white scale on the basis of erythema. It can occur in any part. When the scale is scraped off, punctate bleeding, film phenomenon, wax drop phenomenon can be seen, and there will be fascicular hair on the scalp.