Psoriasis, which is an inflammatory condition that can affect the skin and joints, may also manifest itself on the scalp as an itchy, flaky scalp. “Topical steroids, vitamin D analogues, and tar-based shampoos are the mainstay of therapy, but sometimes systemic medicines or local injections are needed,” Finney says. To find out whether you have psoriasis or dandruff, he advises seeking a dermatologist for an exam.
What causes it?
As with eczema found elsewhere on your body, it depends. “The cause can range from underlying medical conditions like Parkinson’s to an allergic reaction to a hair dye,” Idriss explains.
If the scalp rash is caused by an allergen that touches your skin, it’s referred to as allergic contact dermatitis. “It’s generally coming from a shampoo conditioner, dry shampoo, hairspray, or products that you’re using that are creating a reaction,” Connecticut-based board-certified dermatologist Mona Gohara says. When patients come to her about their scalp eczema, the first thing she finds out is whether they’ve been using any new or different hair-care products — or have recently dyed their hair.
Dandruff, one of the common symptoms of scalp irritation, can also be a result of underlying medical conditions that can disrupt the microbiome of the skin. People who suffer from dandruff generally produce too much sebum in their scalp due to a genus of fungi called Malassezia, which is naturally found in your skin microbiome, but wreaks havoc when there is too much of the fungi producing oleic acid waste.
“Especially when the weather is warmer and more humid, and sweating causes oil to become trapped on the skin,” New York City-based board-certified dermatologist Joshua Zeichner explains. “This creates an environment that allows for overgrowth of yeast, driving inflammation.” People with Parkinson’s disease, for example, can develop oilier-than-usual skin on their face and scalp, which can lead to seborrheic dermatitis.
Unfortunately, when looking for soothing solutions, don’t reach for the hydrating conditioner right away. “Many people see flakes on the skin and think that they need to apply moisturizers or oils,” Zeichner says. “However, this actually can make matters worse, allowing even more yeast to grow in the oily environment.”
Should I treat scalp eczema differently than I would eczema on my body?
It’s less about treating scalp irritation differently from eczema on the rest of your body than figuring out whether your symptoms triggered by irritants or by underlying medical conditions that disrupt your skin’s balance. That can be difficult to figure out without seeking professional advice from a dermatologist. “Avoiding triggers is essential to minimize worsening of symptoms,” Idriss explains. “Hence, the importance of seeking help from a board-certified dermatologist who can help you narrow down the cause through various testing methods — in particular, patch-testing.”