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Some patients’ disease may persist through adulthood. In others, a tendency for dry
and irritable skin that easily develops eczematous changes may persist after AD
resolves. A propensity for recurrent hand dermatitis may remain in adults who had AD in
their childhood. Many children later on develop allergic rhinitis or bronchial asthma.
3.10.2. Seborrheic Dermatitis
Seborrheic dermatitis is a papulosquamous disorder patterned on the sebum-rich
areas of the scalp, the face, and the trunk. In addition to sebum, this dermatitis is
linked to Pityrosporum ovale, immunologic abnormalities, and activation of
complement. It is commonly aggravated by changes in humidity, trauma (eg,
scratching), seasonal changes, and emotional stress. The severity varies from mild
dandruff to exfoliative erythroderma. Seborrheic dermatitis may worsen in Parkinson
disease and in AIDS.
Seborrheic dermatitis is associated with normal levels of P ovale but an abnormal
immune response.
The incidence of seborrheic dermatitis is 3-5%, with a worldwide distribution. In
infants, it occurs as cradle cap or commonly as a flexural eruption or rarely as
erythroderma.
Clinical presentation
Skin lesions present as greasy scale over red, inflamed skin. Infectious eczematoid
dermatitis, with oozing and crusting, suggests secondary infection. A seborrheic
blepharitis may occur independently.
Distribution follows the oily and hair-bearing areas of the head and the neck, such as
the scalp, the forehead, the eyebrows, the lash line, the nasolabial folds, the beard,
and the postauricular skin. Presternal or interscapular involvement is more common
than the nonscaling intertrigo of the umbilicus, axillae, inframammary and inguinal
folds, perineum, or anogenital crease that may also be present.
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