Seborrhoeic dermatitis
Overview
Seborrhoeic dermatitis (also seborrheic dermatitis AmE
, seborrhea, informally seb derm) (also known as "seborrheic eczema") is an inflammatory skin disorder affecting the scalp, face, and torso
. Typically, seborrheic dermatitis presents with scaly, flaky, itchy, and red skin. It particularly affects the sebaceous-gland-rich areas of skin. In adolescents and adults, seborrhoeic dermatitis usually presents as scalp scaling (dandruff) or as mild to marked erythema
of the nasolabial fold
.
The cause of seborrhoeic dermatitis remains unknown, although a yeast
that is part of the normal skin flora, Malassezia furfur, likely plays a key role.
Most cases of seborrhoeic dermatitis likely involve an inflammatory reaction to the proliferation of the yeast Malassezia, though this hasn't been proven.
The main species found in the scalp is Malassezia globosa, others being Malassezia furfur
(formerly known as Pityrosporum ovale) and Malassezia restricta.
American English
American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
, seborrhea, informally seb derm) (also known as "seborrheic eczema") is an inflammatory skin disorder affecting the scalp, face, and torso
Torso
Trunk or torso is an anatomical term for the central part of the many animal bodies from which extend the neck and limbs. The trunk includes the thorax and abdomen.-Major organs:...
. Typically, seborrheic dermatitis presents with scaly, flaky, itchy, and red skin. It particularly affects the sebaceous-gland-rich areas of skin. In adolescents and adults, seborrhoeic dermatitis usually presents as scalp scaling (dandruff) or as mild to marked erythema
Erythema
Erythema is redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin. It occurs with any skin injury, infection, or inflammation...
of the nasolabial fold
Nasolabial fold
The nasolabial folds, commonly known as "smile lines" or "laugh lines," are facial features. They are the two skin folds that run from each side of the nose to the corners of the mouth. They separate the cheeks from the upper lip...
.
The cause of seborrhoeic dermatitis remains unknown, although a yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
that is part of the normal skin flora, Malassezia furfur, likely plays a key role.
Most cases of seborrhoeic dermatitis likely involve an inflammatory reaction to the proliferation of the yeast Malassezia, though this hasn't been proven.
The main species found in the scalp is Malassezia globosa, others being Malassezia furfur
Malassezia furfur
Malassezia is a genus of fungi. Malassezia is naturally found on the skin surfaces of many animals, including humans. In occasional opportunistic infections,...
(formerly known as Pityrosporum ovale) and Malassezia restricta.
