Seborrheic dermatitis is a type of eczema that causes itchy patches, rashes, and dandruff on the face, scalp, and chest. There is no single known cause of the skin condition. Overgrowth of a type of yeast, known as Malassezia yeast, may contribute to inflammation and symptoms in seborrheic dermatitis.
Seborrheic dermatitis is associated with a few different risk factors, which increase a person’s likelihood of developing it. Some risk factors are inherited and others are environmental. Inherited risk factors are passed down through family members and can’t be controlled. Environmental risk factors include exposure to certain medications and complications from other skin conditions.
Researchers are still working to pinpoint the exact cause of seborrheic dermatitis. Currently, they believe it’s caused by a combination of factors. On almost every part of the skin (aside from the palms of the hands and soles of the feet), there are sebaceous glands. These glands produce sebum — an oil that helps keep the skin moisturized and protects it from bacteria and viruses. Seborrheic dermatitis symptoms tend to develop in areas with more sebaceous glands, such as the scalp, face, and chest.
Researchers have looked at the relationship between Malassezia yeast and seborrheic dermatitis. However, there isn’t enough evidence to say that an overgrowth of Malassezia yeast causes seborrheic dermatitis. Malassezia yeast grows on everyone’s skin, and it’s often found in the sebum on areas commonly affected by seborrheic dermatitis.
Some studies suggest that in people with seborrheic dermatitis, the immune system overreacts to Malassezia yeast and its byproducts. Others theorize that the yeast might irritate the skin, but doesn’t cause an immune reaction. Even still, doctors and dermatologists have found that antifungal medications, which decrease yeast growth, can help clear the skin of seborrheic dermatitis symptoms.
Inherited risk factors are passed down from parents to children through their DNA. Researchers believe that some inherited gene changes may contribute to the development of seborrheic dermatitis. Having a family member with dermatitis or a general skin inflammation disorder increases your chances of developing seborrheic dermatitis.
Researchers have found 11 different gene changes and protein deficiencies associated with seborrheic dermatitis. These changes mainly affect the functioning of immune cells in the skin and prevent them from working properly. As a result, the skin can become infected or irritated more easily by factors like an overgrowth of Malassezia yeast, which could lead to chronic (ongoing) inflammation and changes in the skin.
One research study found that HLA proteins may contribute to an increased risk of seborrheic dermatitis. These proteins are found on the outside of your cells (except red blood cells), and they tell your immune system which cells belong to your body and which ones don’t. Another study looking at people with seborrheic dermatitis, acne, psoriasis, and eczema found that certain gene changes may be associated with the development of these conditions.
According to the American Academy of Dermatology, people of all ages and skin colors can develop seborrheic dermatitis. However, the condition is much more likely to affect newborn infants up to 3 months old (called cradle cap) and adults between the ages of 30 to 60. Teenagers going through puberty may also develop seborrheic dermatitis. The condition tends to affect men more than women. Researchers believe that male sex hormones called androgens play a role.
Environmental risk factors and comorbidities can also increase a person’s chances of developing seborrheic dermatitis. These include underlying health conditions and medications, including those used to treat associated health conditions.
Seborrheic dermatitis is associated with skin inflammation and disruption of the protective skin barrier. Oftentimes, people will have other skin conditions in addition to seborrheic dermatitis. These may include:
The risk of seborrheic dermatitis is higher if you have certain health conditions, including:
Seborrheic dermatitis is more common in people with an impaired immune system, including those with HIV or AIDS. Researchers estimate that around 35 percent of people with early HIV infection and 85 percent of those living with AIDS develop seborrheic dermatitis. The symptoms of seborrheic dermatitis also tend to be more severe in people with HIV/AIDS and may occur in parts of the body where they’re usually less common.
The American Parkinson Disease Association has found that people with neurological diseases, such as Parkinson’s disease, also experience seborrheic dermatitis more frequently. Parkinson’s disease causes dysfunction of the autonomic nervous system, which can affect functioning of the sebaceous glands. As a result, people with Parkinson’s disease tend to have more oily skin on the scalp and face, which can lead to seborrheic dermatitis symptoms.
Not everyone with these health conditions will develop seborrheic dermatitis. Oftentimes, treating these health conditions will help address seborrheic dermatitis symptoms. If you have seborrheic dermatitis in addition to other chronic health conditions, talk to your doctor or dermatologist about how to best treat all of your symptoms.
People with mental health conditions like anxiety, eating disorders, and depression are more prone to seborrheic dermatitis. Having seborrheic dermatitis can also make these mental health conditions worse. Stress is also a common trigger for the initial onset and flares of seborrheic dermatitis. Although stress and similar intense emotions may not directly cause seborrheic dermatitis, they may play a role in the development and flaring of symptoms.
Seborrheic dermatitis is a potential side effect of some medications. Examples include:
Seborrheic dermatitis can’t be prevented, and there currently is no cure. Sometimes, treating an underlying health condition may help treat seborrheic dermatitis, but it may not always resolve on its own. Seborrheic dermatitis is a chronic skin disease that has periods of flares and clear skin. There are steps you can take to prevent triggering flares and worsening symptoms. Treatments for seborrheic dermatitis include medicated shampoos to help with dandruff, antifungal medications, topical corticosteroids, and calcineurin inhibitors.
If you notice seborrheic dermatitis symptoms, talk to your doctor or dermatologist. They can prescribe you treatments to help manage the condition and clear your skin. Practicing good skin care and personal hygiene habits can also help keep some symptoms under control.
MySebDermTeam is the social network for people with seborrheic dermatitis and their loved ones. On MySebDermTeam, members come together to ask questions, give advice, and share their stories with others who understand.
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