Seborrhoeic dermatitis (also Seborrheic dermatitis AmE, seborrhea) (also known as "Seborrheic eczema") is a skin disorder affecting the scalp, face, and trunk causing scaly, flaky, itchy, red skin. It particularly affects the sebum-gland rich areas of skin.
Seborrhoeic dermatitis may be visually unpleasant and moderately itchy but is a harmless condition. The condition is often persistent but is easily controlled using readily available medication. After treatment, the condition may recur after a time lapse of months or years.
As with other dermatitis conditions, seborrhoeic dermatitis is often loosely defined as a form of eczema although it differs from other more serious conditions more properly defined as eczema.
The cause of seborrhoeic dermatitis remains unknown, although many factors have been implicated. The widely present yeast, Malassezia furfur (formerly known as Pityrosporum ovale), is involved, as well as genetic, environmental, hormonal, and immune-system factors. The claim that seborrhoeic dermatitis is an inflammatory response to the yeast has not been proven. Those afflicted with seborrhoeic dermatitis have an unfavourable epidermic response to the infection, with the skin becoming inflamed and flaking.
Acute form of seborrhoeic dermatitis on scalp
In children, excessive vitamin A intake can cause seborrhoeic dermatitis. Lack of biotin, pyridoxine (vitamin B6) and riboflavin (vitamin B2) may also be a cause.
Soaps and detergents such as sodium laureth sulfate may precipitate a flare-up, as they strip moisture from the top layers of the skin. Accordingly a suitable alternative should be used instead.
Among dermatologist-recommended treatments are shampoos containing coal tar, ciclopiroxolamine, ketoconazole, selenium sulfide, or zinc pyrithione. For severe disease, keratolytics such as salicylic acid or coal tar preparations may be used to remove dense scale. Topical terbinafine solution (1%) has also been shown to be effective in the treatment of scalp seborrhoea, as may lotions containing alpha hydroxy acids or corticosteroids (such as fluocinolone acetonide). Pimecrolimus topical lotion is also sometimes prescribed.
Topical application of a water-soluable ointment containing 50mg of Vitamin B6 per gram of ointment has been used as an effective treatment.
Several nutritional supplements are recommended including: 3 mg twice per day of Biotin,  B-complex, 20-30 mg per day of Zinc, and 1 tbsp per day of flaxseed oil.
Chronic treatment with topical corticosteroids may lead to permanent skin changes, such as atrophy and telangiectasia.
UV-A and UV-B light inhibit the growth of M. furfur, although caution should be taken to avoid sun damage.
Interesting article. I have this condition myself, especially during the winter. Sunlight does help, as does using anti-dandruff shampoo (even though I'm bald!). I was interested to see the yeast connection. I have had other skin infections that my doctor has said are yeast connected. Of course eating carbs is just the food the yeast need to thrive. Yuck!