Generalized seborrheic erythroderma is rare. It is more often seen in AIDS, CHF, Parkinson disease, and in immunocompromised premature infants. Plaques are rare. From the scalp, seborrheic dermatitis can spread onto the forehead, posterior neck and postauricular skin, like psoriasis. Skin lesions present as branny or greasy scale over red, inflamed skin.
Hypopigmentation is seen in blacks.
Infectious eczematoid dermatitis, with its oozing and crusting, suggests secondary infection. A seborrheic blepharitis may occur independently. Distribution follows the oily and hair-bearing areas of head and neck, such as the scalp, forehead, eyebrows, lash line, nasolabial folds, beard and postauricular skin. Presternal or interscapular involvement is more common than the nonscaling intertrigo of the umbilicus, axillae, inframammilae inguinal fold, perineum or anogenital crease that may also be present. Two distinct truncal patterns can occasionally occur.