Seborrheic dermatitis, also called seb derm, is a skin condition that usually affects oily body parts and causes itchy, inflamed skin, scaly patches, and dandruff. The most affected areas are the sides of the nose, hairline, eyebrows, behind ears, and eyelids, but other body parts might also be affected. It is a lifelong condition that may disappear and fare up occasionally. I will review seborrheic dermatitis causes and triggers in this article based on my experience as a doctor and skin therapist.
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What Causes Seborrheic Dermatitis?
There are few seborrheic dermatitis causes and triggers. Let’s discuss them.
- Oily Skin. If your skin is naturally oily, you are more likely to get seborrheic dermatitis. The fungus that causes this condition feeds on oil and sebum produced by the oily glands. Hormonal disbalance or long-term use of hormonal medications is the leading cause of oily skin.
- The Fungus. A yeast called Malassezia (formerly known as Pityrosporum ovale) is a part of the normal skin microbiome. It is a large group of Malassezia species. These fungi depend on oil, so they mostly live in oily body parts like the face and scalp (but can live anywhere except feet).
- Men. They tend to develop seborrheic dermatitis more often than women.
- Caucasians. People with white and fair skin tend to get this type of dermatitis more often. The farther they live from the equator, the more chances they get seborrheic dermatitis.
- Immunodeficiency. Immunodeficiency leads to the overgrowth of Malassezia fungus (same as Candida) and makes the body more susceptible to various illnesses. Some immunosuppressive conditions are cancer (especially lymphomas), HIV, alcoholism, organ transplants, eating disorders, recovery from a stroke, Crohn’s disease, and the lack of vitamins.
- Neurological Conditions and Psychotropic Medications. Some neurological conditions were strongly associated with seborrheic dermatitis. Among the conditions are Parkinson’s disease, epilepsy, spinal cord injury, depression, and facial nerve palsy. Some psychotropic medications associated with Malassezia dermatitis are lithium, buspirone, chlorpromazine, and haloperidol decanoate. These medications may cause seborrheic dermatitis.
- Other Skin Diseases and Skin Medications. Psoriasis, acne, and rosacea may increase the risk of developing seborrheic dermatitis. It is possible to have two skin conditions. Also, sometimes seborrheic dermatitis is mistaken for other diseases. The article “Rosacea vs. Seborrheic Dermatitis” describes the similarities and differences between the two conditions very well. Psoralen and interferon are medications used to treat other skin diseases but might also trigger seborrheic dermatitis.
What Triggers Seborrheic Dermatitis?
Seborrheic dermatitis is a lifelong disease. It may resolve after treatment and come back when some factors trigger it. The major seb derm triggers are:
- Stress (psychological or physical), lack of sleep
- Hormonal changes
- Other diseases (decreases immunity)
- Harsh detergents and cosmetics (containing alcohol)
- Cold, dry weather
- Changing seasons – worse in winter, improving in summer (probably, the UV rays reduce the yeast count)
- Nutritional deficits, alcoholism
What Causes Seborrheic Dermatitis on Scalp?
There are two types of Seborrheic dermatitis on the scalp:
- Infant Type/Cradle Cap. A baby develops crusty yellow or reddish, scaly patches on the scalp. The exact causes are unknown. Oil overproduction in the sebaceous glands and Malassezia yeast might be among the causative factors. Changing hormones in the mother’s body during pregnancy might cause the baby’s oil glands to overproduce.
- Adult Type. Or it is simply called dandruff. There is no erythema. Only scaly patches or dandruff are seen on the head. Usually, the condition is not itchy, but itching sometimes slightly. In more severe cases, erythematous plaques and solid patches of thick-crusted skin may develop. In most severe cases, the head may become yellow and greasy; secondary infection could occur. Same seborrheic dermatitis causes may cause or trigger seb derm on the scalp: immunodeficiency, harsh cosmetics, oily head skin, and overgrowth of the Malassezia yeast.
What Makes Seborrheic Dermatitis Worse?
Besides all the causes and triggers discussed above, some foods may worsen seborrheic dermatitis. The foods I am talking about contain yeast or mold. These foods are:
- All kinds of bread (except the ones that do not contain yeast)
- Cheeses (yeast finishes cheese maturation, some cheeses contain mold)
- Wine (yeasts convert sugars in the juice into alcohol in wine), but wine has many antioxidants, so it’s only up to you whether you quit wine.
- Beer – a massive source of yeast in every kind of beer. Same as with wine: yeast eats up sugars and creates alcohol.
- Excessive carbohydrates, high glycemic foods – usually do not contain yeast but feed the fungus. Yeast likes sugar and carbs, and the more you these foods, the more yeast overgrowth you will experience.
Probiotics may help to restore healthy gut and body microbiome balance.
In addition, pro-inflammatory foods may exacerbate inflammation. The pro-inflammatory foods are:
- Red meats
- Processed meats (sausage)
- Organ meats (liver, heart, kidney, brain)
- White fish (non-oily fish)
- Refined grains (bread, pasta, white rice, breakfast cereal)
- Sweetened beverages (soda)
- Snack foods (cookies, chips, and others)
- Fried foods
Try to change your diet. Some anti-inflammatory foods are leafy green vegetables (like spinach, kale, and collards), dark yellow vegetables (such as carrots, pumpkins, sweet potatoes, and winter squash), oily fish (i.e., salmon, tuna, herring, and sardines), olive oil, nuts, fruit and berries, tomatoes (contrary to popular belief), coffee, tea, fruit juice with no added sugar.
The exact cause of seborrheic dermatitis is unknown. Many factors and triggers may contribute to this condition. The leading seborrheic dermatitis causes are oily skin, immunodeficiency, and overgrowth of Malassezia yeast.
Some other illnesses and the use of medication might also trigger seb derm. In addition, cold, dry weather (with little or no UV rays), harsh detergents and cosmetics, yeast containing and proinflammatory foods may worsen seborrheic dermatitis.
- Saunte, D. M., Gaitanis, G., & Hay, R. J. (2020). Malassezia-Associated Skin Diseases, the Use of Diagnostics and Treatment. Frontiers in Cellular and Infection Microbiology, 10. Read
- Seborrheic dermatitis & cradle cap in infants. National Eczema Society. Read
- Bintsis T. Yeasts in different types of cheese. AIMS Microbiol. 2021 Nov 8;7(4):447-470. doi: 10.3934/microbiol.2021027. PMID: 35071942; PMCID: PMC8712537. Read
- Wine Savvy. 10 Surprising Ingredients You Probably Didn’t Know Were in Your Wine. Wine Cooler Direct. Read
- Foods that fight inflammation. Harvard Health Publishing. Read