DEAR MAYO CLINIC: My teenage daughter’s hair has become oily over the past couple of months, and it’s causing a lot of small pimples in her hairline and on her forehead. What could cause this change in her hair — it was always on the dry side until recently — and what’s the best way to treat acne on the scalp?
ANSWER: During the teenage years, it’s common to have more oil on the skin, including the scalp. As a result of hormone changes that happen during puberty, children that never had oily skin or hair before can begin to develop it as teens. Over-the-counter remedies usually can control breakouts on the scalp. But if the problem persists, see your daughter’s primary care provider for further evaluation and treatment.
The areas of the body typically affected by acne are those that have the most oil glands — also called “sebaceous glands.” They include the face, forehead, chest, upper back and shoulders. The hair follicles are susceptible to acne because they are connected to oil glands.
During puberty, hormones called “androgens” increase throughout the body. That causes the sebaceous glands to enlarge and make more oil, or sebum. But excess oil alone doesn’t cause acne. It’s typically a combination of the oil and dead skin cells, along with bacteria called Propionibacterium acnes, or P. acnes. Those bacteria grow on the skin all the time. When oil production increases during puberty, however, the Propionibacterium acnes have a more readily available food source, so they grow and multiply more easily.
Whiteheads, blackheads and pimples develop when oil, dead skin cells and bacteria clog hair follicles. This combination of factors — clogged follicles or pores, sebum production and Propionibacterium acnes — is the reason multiple medications often are needed to treat acne successfully.
When excess oil and acne affect the hair and scalp, a good first step is to try an over-the-counter anti-dandruff shampoo. These shampoos reduce the amount of oil on the scalp. Different brands have different active ingredients, such as pyrithione zinc, salicylic acid or selenium sulfide. Choosing two anti-dandruff shampoos with active ingredients that are not the same, and then switching back and forth between them, provides the best results for reducing oil on the scalp over time. For the most effective oil control, encourage your daughter to shampoo every other day to daily.
An anti-bacterial soap also can help treat pimples on the scalp if there are not many of them or if they are confined to a small area. As the number of pimples on the scalp increases, it can be difficult to use anti-bacterial soaps in this fashion, as they don’t work well over large areas of the scalp.
For the acne on her forehead, a wash that contains benzoyl peroxide, in combination with a topical retinoid such as adapalene, can be useful. These medications are available over the counter.
Contrary to popular myth, acne is not caused by eating greasy food or chocolate, although diets with a high glycemic index may raise the risk for developing acne. Dirty skin isn’t the problem, either. Scrubbing skin that’s affected by acne too hard, or cleaning it with harsh chemicals or soaps can worsen the problem. If your daughter wears cosmetics, that won’t necessarily affect acne, especially if she uses oil-free makeup that doesn’t clog pores and she removes her makeup before going to bed.
If acne persists despite treatment with over-the-counter products, make an appointment for your daughter to see her primary care provider. Sometimes prescription shampoos can help reduce oil on the scalp. And pimples that appear on the scalp may be eliminated using a prescription-strength topical antibiotic. Acne can be stubborn, so it’s common for a combination of medications to be prescribed to treat it effectively. — Dr. Megha Tollefson, Dermatology, Mayo Clinic, Rochester, Minnesota