Seborrhoeic dermatitis Classification and external resources
ICD-10	L21.
ICD-9	690
DiseasesDB	11911
MedlinePlus	000963
eMedicine	derm/396
MeSH	D012628

Seborrhoeic eczema (also Seborrheic dermatitis AmE, seborrhea) 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.

Causes

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,^[1][2] as well as genetic, environmental, hormonal, and immune-system factors.^[3][4] A theory that seborrhoeic dermatitis is an inflammatory response to the yeast has not been proven.^[5] 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.^[6] Lack of biotin,^[7] pyridoxine (vitamin B6)^[7][8] and riboflavin (vitamin B2)^[7] may also be a cause.

Hair loss

Side effects to inflammation may include temporary hair loss. If severe outbreaks are untreated for extended intervals, permanent hair loss may result, because of damage to hair follicles.

Treatments

Soaps and detergents such as sodium laureth sulfate^{citation needed} may precipitate a flare-up, as they strip moisture from the top layers of the skin, and the drying property of these can cause flare-ups and may worsen the condition.^{citation needed} Accordingly a suitable alternative should be used instead.

Among dermatologist recommended treatments are shampoos containing coal tar, ciclopiroxolamine, ketoconazole, selenium sulfide, or zinc pyrithione.^[9] 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,^[10] as may lotions containing alpha hydroxy acids or corticosteroids (such as fluocinolone acetonide). Pimecrolimus topical lotion is also sometimes prescribed.

Chronic treatment with topical corticosteroids may lead to permanent skin changes, such as atrophy and telangiectasia.^[11][12]

UV-A and UV-B light inhibit the growth of M. furfur,^[13] although caution should be taken to avoid sun damage.

According to the American Academy of Family Physicians(AAFP), one treatment that has proven successful, especially when steroid topicals and shampoos aren't working, and the patient continues to suffer from rapid hair loss and rashes, has been low doses(10mg-30mg daily) of the perscription drug Accutane,(Isotretinoin). The exact mechanism isn't known, but it is thought to work by reducing sebum, which plays an important role in seborrhoeic dermatitis. Patients should be evaluated monthly, while examing the proper liver functions when putting a patient on accutane therapy. Special screening should be in place for women patients, because of the risk of birth defects. This therapy can last, when the condition is chronic and the isotretinoin dose is low, for years. But, patients should be given a one to two month break off this particular therapy every 6 months to see if the condition still is affecting the patient.^[14]

Those with seborrhoeic dermatitis might benefit from biotin supplements.^{citation needed} One might also try a humidifier by the bed, as well as a gentle moisturizer with or without oatmeal.^{citation needed} Applying milk of magnesia may help clear up seborrheic dermatitis; one may apply on the face while showering and rinse off at the end of the shower.^[15]

Plant-based treatments

Main article: phytotherapy

The World Health Organization mentions Aloe vera gel as a yet to be scientifically proven traditional medicine treatment for Seborrhoeic dermatitis.^[16]

• Arctium lappa (Burdock) oil^[17]
• Chelidonium majus (Celandine)^[17]
• Glycyrrhiza glabra (Licorice)^[17]
• Melaleuca (Tea tree) species^[17]
• Plantago (Plantain) species^[17]
• Symphytum officinale (Comfrey)^[17]
• Zingiber officinale (Ginger) root juice^[17]
• Ledebouriella Seseloides (Fang Feng) ^[17]
• Smilax China (Smilax china) ^[17]
• Trichosanthes Kirilowii (Snakegourd) ^[17]
• Glycyrrhiza Uralensis (gān cǎo) ^[17]
• Coptis Chinensis (Chinese goldthread) ^[17]
• Phellodendron Amurense (Huang Bai) ^[17]
• Sophora Flavescens ^[17]
• Centella Asiatica (Gotu Kola) ^[17]

See also

• Echinopsis peruviana

References

External links

• Seborrhoeic Dermatitis at DermNet
• Seborrheic Dermatitis: An Overview - July 1, 2006 -- American Family Physician