• Superficial reddened small bumps and scaly eruptions occurring on the scalp, cheeks, and skin folds (armpit, groin, and neck)
• Usually does not itch
• Seasonal; worse in winter
Seborrheic dermatitis is a common skin condition with an appearance similar to eczema. It may be associated with excessive oiliness (seborrhea) and dandruff. The scales may be yellowish and either dry or greasy. The reddened, scaly bumps may coalesce to form large plaques or patches.
Seborrheic dermatitis often occurs in infancy as “cradle cap” (usually between 2 and 12 weeks of age) and has a prognosis of lifelong recurrence, tending to be worse with advancing age.
Causes
The cause of seborrheic dermatitis is unknown. Genetic predisposition, emotional stress, diet, hormones, and infection with yeast-like organisms have all been implicated. Seborrheic dermatitis is now recognized as one of the most common manifestations of AIDS, affecting as many as 83% of AIDS patients. This recent observation has given increased credence to the infection theory of seborrheic dermatitis.
Seborrheic dermatitis, although not primarily an allergic disease, has been associated with food allergies—67% of people with seborrheic dermatitis develop some form of allergy by 10 years of age.1
Therapeutic Considerations
A deficiency of one or more B vitamins may be involved in seborrheic dermatitis. For example, the underlying factor in infants appears to be a biotin deficiency.2 A syndrome clinically similar to seborrheic dermatitis has been produced by feeding rats a diet high in raw egg white, which is high in avidin, a protein that binds biotin and makes it unavailable for absorption. Since a large portion of the human biotin supply is provided by intestinal bacteria and since newborns have a sterile gastrointestinal tract, it has been postulated that the absence of normal intestinal flora may be responsible for biotin deficiency in infants.2 A number of studies have demonstrated successful treatment of seborrheic dermatitis with biotin in both the nursing mother and the infant.3
In adults, treatment with biotin alone is usually of no value. It must be used in combination with other B vitamins (pyridoxine, pantothenic acid, niacin, thiamine, etc.) that are vital for proper skin metabolism.
Vitamin B6
Taking a drug that causes vitamin B6 deficiency (4-deoxypyridoxine) and placing rats on a vitamin B6–deficient diet cause skin lesions indistinguishable from seborrheic dermatitis.4 Vitamin B6 has been shown to be effective in a form of seborrhea (seborrhea sicca) that involves only the scalp (dandruff), brow, nasolabial folds, and beard area, with varying degrees of greasy adherent scales on a reddened base.
Folic Acid and Vitamin B12
Oral treatment with folic acid has been only moderately successful; the best results are obtained with a special form, tetrahydrofolate.5 It should also be used in combination with vitamin B12. Injections of vitamin B12 have been shown to be very effective in many cases.6 This may be due to vitamin B12’s role as a cofactor in converting folic acid into its active form, tetrahydrofolate.
Aloe Vera Gel
Aloe vera gel can be quite helpful when applied topically. In one double-blind trial involving people with seborrheic dermatitis, the application of a 30% crude aloe emulsion cream twice a day for four to six weeks produced improvements in scaling and itching in 62% of subjects, compared with improvements in only 25% of the placebo group.7
Tea Tree Oil
Tea tree (Melaleuca alternifolia) oil may be of benefit in the treatment of seborrheic dermatitis owing to its antifungal effects.8 It seems to be especially helpful when there is involvement of the scalp. In a study of 126 patients, treatment with 5% tea tree oil shampoo produced a 41% improvement in severity vs. 11% in the placebo group.9 Tea tree oil shampoos are available, or you may add the oil to your favorite shampoo (1 tbsp tea tree oil for every 8 oz shampoo).
QUICK REVIEW
• Seborrhea may be due to a B vitamin deficiency.
• A biotin deficiency is the most frequent cause of cradle cap.
• Aloe vera gel applied topically can help.
TREATMENT SUMMARY
For infants, biotin supplementation (3 mg twice per day) and control of food allergies are the keys. For adults, supplementing with large doses of vitamin B complex within a high-potency multiple vitamin is the key therapy. We also recommend optimal intake of essential fatty acids, using both flaxseed oil and fish oils.
Rule out food allergies. For nursing infants, the food allergies of the mother should be considered. Otherwise, the recommendations in the chapter “A Health-Promoting Diet” should be followed.
• A high-potency multiple vitamin and mineral formula as described in the chapter “Supplementary Measures”
• Fish oils: 1,000 mg EPA + DHA per day
• Flaxseed oil: 1 tbsp per day
• One of the following:
Grape seed extract (>95% procyanidolic oligomers): 100 to 300 mg per day
Pine bark extract (>95% procyanidolic oligomers): 100 to 300 mg per day
Some other flavonoid-rich extract with a similar flavonoid content, super greens formula, or another plant-based antioxidant that can provide an oxygen radical absorption capacity (ORAC) of 3,000 to 6,000 units or more per day
• Probiotic (Lactobacillus species and Bifidobacterium species): a minimum of 5 billion to 10 billion colony-forming units
• Aloe vera gel: apply twice per day to affected areas
• Tea tree oil shampoo: wash hair and scalp daily