As humans, we constantly form new epidermal cells. When these cells get closer to the surface of the skin, the cell slowly dies and the visual manifestation of this is flakes. This is a normal process that happens to everyone all the time. In some people, the rate of epidermal cell development is accelerated.

Dandruff and seborrheic dermatitis are conditions involving the increased rate of shedding of the topmost layer of the skin called the epidermis. The most common form of seborrheic dermatitis which only involves the scalp is dandruff.  Dandruff can be asymptomatic or cause mild flaking and itching. The best way to treat dandruff is to use over the counter (OTC) medicated shampoos like pyrithione zinc, ketoconazole, or selenium sulfide. These meds can be left on for a few minutes and then rinsed off. They can be used daily or 2-3 times per week until the symptoms are gone. Recurrence can be prevented by continuing to use one of these products 2-3 times per week.

With seborrheic dermatitis, there is a greater turnover rate of skin cells than in dandruff. The rest of this article focuses on seborrheic dermatitis

Seborrheic Dermatitis

The frequency of Seborrheic Dermatitis

As a pediatrician, I encounter seborrheic dermatitis at least 3 times a day on the infants I see. Many people know this condition as “cradle cap.” Seborrheic dermatitis is the scale on a 3-month-olds scalp, the flakes on their eyebrows, and the redness and moisture under the neck folds, behind the ears, in the armpits, and in the groin. About 1 in 3 infants are affected [1]. In pediatric offices in some countries, seborrheic dermatitis can account for 4.5% of problems seen in children younger than 6 years [1].

Seborrheic dermatitis is also found during puberty and in adulthood. It is thought that 1-3% of adults are affected. The peak prevalence in adults is during their 30s and 40s. The affected areas of the body that become red, itchy, flaky, and scaly are very similar to that which is found in infants: the face (especially below the hairline on the forehead, in and between the eyebrows, in the crease between the nose and the cheeks, and in the mustache and beard area in men with facial hair), upper chest, armpits, behind the ears and inguinal folds [2,3].

Of note, seborrheic dermatitis gets worse during cold and dry winter months and during times of stress and tends to improve in the summer possibly from sun exposure [3].

Financial Burden

The estimated financial burden of this disease is immense. “It is estimated that at least 50 million Americans suffer from dandruff, who spend $300 million annually on over-the-counter products to treat scalp itching and flaking.” [2] Outpatient office visits alone for seborrheic dermatitis (SD) cost $58 million in the United States in 2004, and $109 million was spent on prescription drugs [2].

“Together with over-the-counter products and hospital services, the total direct costs of SD were estimated to be $179 million, plus another $51 million indirect costs in the form of lost work days. In addition, because SD frequently occurs on the face and other visible areas, it has significant negative effects on patients’ quality of life (QOL) in the form of psychological distress or low self-esteem; the willingness to pay for relief of the symptoms was $1.2 billion.” [2].

What causes seborrheic dermatitis?

Most sources concur that a fungal species (yeast) called Malassezia is involved. This yeast metabolizes the oils produced by sebaceous glands producing a more irritating acid that starts the inflammatory cascade that causes the redness and leads to the overproduction of the topmost layer of skin cells (stratum corneum) causing the flaking and scaling.

With this overgrowth, the barrier function of the skin is disrupted and it loses moisture. Then you get more yeast and more inflammation and the cycle continues until the hormonal milieu (transitioning from infancy to childhood or childhood to puberty) changes sebaceous gland activity or we make a medical intervention.

The immune system and neurological system also play an unknown role in seborrheic dermatitis. People with an impaired immune system have an increased prevalence of seborrheic dermatitis and people with Parkinson disease have increased sebum production and when treated with L-dopa their seborrheic dermatitis improves [3].

Differential Diagnosis

What else shares similar signs or symptoms to those of seborrheic dermatitis? Other conditions doctors may need to consider are psoriasis, rosacea, allergic contact dermatitis, tinea versicolor, pityriasis rosea, tinea corporis, secondary syphilis, lupus erythematosus, and pemphigus foliaceous [3].

How does one treat seborrheic dermatitis?

Children:

In an informal study conducted in Houston, 7 out of 10 pediatricians recommended an adult OTC (Over The Counter) anti-dandruff shampoo with pyrithione zinc or selenium sulfide to treat seborrheic dermatitis, also called “cradle cap.” In refractory cases, pediatricians sometimes have to also add a topical steroid for a short duration.

Many families try coconut oil, baby oil, olive oil or petroleum jelly to loosen scales and then use regular shampoo. However, many infants do not improve with those treatments.

Adult anti-dandruff shampoos were suggested due to the lack of an OTC shampoo specifically designed for children of all ages. These shampoos work to address the issue, but they were designed for the skin of an adult and many times have strong fragrances or alcohols or dyes that are not suited to dry, irritated skin.

I have developed a new option for children of all ages (and adults) called Dr. Eddie’s Happy Cappy. It is the first OTC shampoo and body wash made specifically for children of all ages with an FDA approved active ingredient, pyrithione zinc. This shampoo is fragrance-free, dermatologist tested, dye free, alcohol free, paraben free and contains the natural ingredient Licorice Root Extract to help soothe redness behind ears, under armpits, and in neck folds.

Adults:

The most common treatment for adults is OTC anti-dandruff & anti-seborrheic dermatitis shampoos like pyrithione zinc, selenium sulfide, ketoconazole, salicylic acid or coal tar. Under the care of a physician, an adult may be prescribed topical antifungal medications like ketoconazole or for short duration they may receive topical steroids or calcineurin inhibitors (another category of topical medication). In Europe topically applied lithium sulfate or lithium gluconate is used to help seborrheic dermatitis in non-scalp areas.

“A 2015 systematic review and meta-analysis including 51 randomized trials with over 9000 participants found that in patients with seborrheic dermatitis of the face and scalp, topical ketoconazole 2% applied once or twice daily was more effective than placebo in improving erythema, pruritus {itching}, and scaling at four weeks.” [3]

Another 2014 study showed that use of topical calcineurin inhibitors (pimecrolimus or tacrolimus) or topical steroids or topical lithium applications all reduced the symptoms of seborrheic dermatitis about the same and did better than placebo. Side effects from these treatments include redness, burning, dryness, and itching [3].

Other topical remedies included in the UpToDate review article, include ones derived from sulfur—precipitated sulfur 3%, colloidal sulfur 3%, or sodium sulfacetamide 10% in cream or lotion base.  They comment that these are, “an old but effective remedy, although patients may object to its odor.” [3]

Oral antifungal agents have also been used for seborrheic dermatitis occupying multiple areas of the body or disease not adequately controlled with topical therapy; however, evidence supporting the use of oral therapies is limited [3].

1. Foley P, Zuo Y, Plunkett A, Merlin K, Marks R. The frequency of common skin conditions in preschool-aged children in Australia: seborrheic dermatitis and pityriasis capitis (cradle cap) Arch Dermatol. 2003;139:318–322.
2. Borda L, Wickramanayake, T. Seborrheic Dermatitis, and Dandruff: A Comprehensive Review J Clin Investig Dermatol. 2015 Dec; 3(2): 10.13188/2373-1044.1000019. Published online 2015 Dec 15. doi:  10.13188/2373-1044.1000019
3. Sasseville, D., Fowler, J., (2018). Seborrheic dermatitis in adolescents and adults. In Corona, R., (Ed.), UpToDate. Retrieved July 20, 2018, from https://www.uptodate.com/contents/seborrheic-dermatitis-in-adolescents-and-adults