Eczema is an umbrella term used to describe a series of skin conditions that share common characteristics, such as dry, itchy or irritated patches of skin with a rash-like appearance. Sometimes people can have more than one type of eczema at the same time.
Each form of eczema has its own set of triggers and treatment requirements. That’s why it’s so important to consult with health care providers who specialize in treating eczema. Dermatologists in particular can help identify which type or types of eczema you may have and how to treat and prevent flare-ups.
Seborrheic dermatitis usually appears with dryness, redness and thick, greasy, white or yellow scales on the scalp, especially around the hairline and behind the ears. This type of eczema often looks like psoriasis, another inflammatory skin disease driven by an overactive immune system, and some patients have both conditions.
“Seborrheic dermatitis isn’t contagious and is not an allergy, though some allergies can mimic it,” said Dr. Peter Lio, clinical assistant professor of dermatology and pediatrics at Northwestern University’s Feinberg School of Medicine. A correct diagnosis, he added, requires careful evaluation by a dermatologist.
An inflammatory reaction to excess Malassezia yeast, an organism that normally lives on the skin’s surface, is the likely cause of seborrheic dermatitis, according to Lio.
“The Malessezia overgrows and the immune system seems to overreact to it, leading to an inflammatory response that results in skin changes,” said Lio, who is the founding director of the Chicago Integrative Eczema Center.
Seborrheic dermatitis can affect people of any age, though it’s most common in infants and adults between the ages of 30 and 60. In infants, the condition usually clears on its own and doesn’t come back. In adults, however, seborrheic dermatitis usually follows a pattern of flaring and clearing that can last for years.
Symptoms of seborrheic dermatitis
Infants with seborrheic dermatitis most often have a form called cradle cap, which appears on their scalps as scaly, greasy patches. They can also develop seborrheic dermatitis on their bottoms, where it can be mistaken for diaper rash, a form of contact dermatitis.
In teens and adults, seborrheic dermatitis forms where skin is oilier. In addition to the scalp, redness, swelling and greasy scaling can develop on the the sides of the nose and in and around the eyebrows, on the mid-chest, upper back and in the armpits and groin area.
The rash can itch uncomfortably, but it’s the redness and scaling that tends to bother patients most, said Lio. “Having a rash in a visible area has a big impact in how we feel about ourselves and how others see us,” he added.
Who gets seborrheic dermatitis and why
Most people who develop seborrheic dermatitis are healthy, and with the exception of infants, the condition is more common among men. Stress and cold, dry weather can trigger flares.
Some medications, including psoralen, interferon and lithium, increase people’s risk of developing seborrheic dermatitis, as do certain medical conditions. Along with psoriasis these include HIV, acne, rosacea, Parkinson disease, epilepsy, alcoholism, depression, eating disorders, and recovery from a stroke or heart attack.
Seborrheic dermatitis can also overlap with atopic dermatitis, especially in infants. “We see this overlap in young adults, as well, usually in those with more severe atopic dermatitis,” Lio said. They can develop a condition that some call head and neck dermatitis that seems to be very closely related to seborrheic dermatitis and is treated similarly.”
Treating seborrheic dermatitis
Treatment for seborrheic dermatitis is aimed at removing scales, reducing itch and calming the inflammation that’s causing redness and swelling.
In infants, using an emollient such as mineral oil or petroleum jelly to gently loosen scale is usually all that’s needed. Care can be more complicated for adults, who often need ongoing treatment and self-care to help prevent flares.
Dermatologists usually begin treating mild cases with a topical anti-fungal cream or medicated shampoo, such as a prescription anti-fungal shampoo or over-the-counter dandruff product.
“For mild cases this may be enough to control symptoms,” said Lio. “If the condition is more severe, we can intermittently add a topical corticosteroid.”
Some people shouldn’t use steroids and for these individuals, dermatologists may prescribe a topical calcineurin inhibitor, a type of nonsteroidal cream.
Good self-care can help keep symptoms under control, Lio said. He advises washing affected areas daily with a gentle, zinc-containing cleanser (2% zinc pyrithione) and following with a moisturizer.
Healthy lifestyle habits can also improve skin. “Stress reduction, eating a healthier diet and getting sufficient sleep can be factors in getting skin better,” said Lio. “While we cannot cure seborrheic dermatitis, lifestyle changes and treatments can make it fade into the background of your life.”