SEBORRHOEA

Seborrhoea , a medical term applied to describe an accumulation on the skin of the normal sebaceous secretion mixed with dirt and forming scales or a distinct incrustation. On the head, where it is commonly seen, it may interfere with the nutrition of the hair and cause partial baldness.

A form of this disease occurs in young infants. The main treatment consists in thoroughly cleansing the parts. The crusts may be softened with oil and the affected skin regularly washed with soft soap and rectified spirit. The sebum frequently accumulates in the sebaceous ducts, giving rise to the minute black points often noticed on the face, back and chest in young adults, to which the term comedones is applied.

A form of this disorder, of larger size and white appearance, is termed milium. These affections may to a large extent be prevented by strict attention to ablution and brisk friction of the skin, which will also often remove them when they begin to appear. The retained secretion may be squeezed out or evacuated by incision and the skin treated with some simple sulfur application.

Seborrhoeic dermatitis is a common, harmless, scaling rash affecting the face, scalp and other areas. It is most likely to occur where the skin is oily. The American spelling is ‘seborrheic’, and ‘dermatitis’ is sometimes called ‘eczema’.

Dandruff (also called ‘pityriasis capitis’) is an uninflamed form of seborrhoeic dermatitis. Dandruff presents as scaly patches scattered within hair-bearing areas of the scalp.

Seborrhoeic dermatitis may appear at any age after puberty. It fluctuates in severity and may persist for years. It may predispose to psoriasis. However, the plaques of psoriasis are more persistent, thicker, and a deeper red colour, with large flakes of white scale. Psoriasis is very likely to affect elbows and knees as well as the scalp. However, sometimes it is difficult to tell psoriasis from seborrhoeic dermatitis on the face, scalp and chest and your doctor may diagnose an overlap condition, known as ‘sebopsoriasis’.

Within the scalp, seborrhoeic dermatitis causes ill-defined dry pink or skin coloured patches with yellowish or white bran-like scale. It may spread to affect the entire scalp.

Seborrhoeic dermatitis is common within the eyebrows, on the edges of the eyelids (blepharitis), inside and behind the ears and in the creases beside the nose. It can result in pale pink round or ring shaped patches on the hairline.

Sometimes it affects the skin-folds of the armpits and groin, the middle of the chest or upper back. It causes salmon-pink flat patches with a loose bran-like scale, sometimes in a ring shape (annular). It may or may not be itchy and can be quite variable from day to day.