Q: I’ve had issues with dandruff off and on for several years and it usually clears up with Head & Shoulders shampoo. This fall my dandruff has worsened, the skin under the flaking areas is red and the flakes are starting to look a yellowish colour. It has started to spread beyond my hair line in the area behind my ears and I have developed a small spot on my chest. Can dandruff spread beyond your scalp? How should I treat this?
The skin all over our body, including our scalp, is constantly shedding. When you have dandruff, the top layer of skin in that area is shedding too quickly and is clumping with the natural oils our skin produces causing the skin flakes we recognize as dandruff.
In a mild to moderate form, dandruff is limited to the scalp area and may also be associated with an itchy scalp. The medicinal ingredient used in most of the Head & Shoulders shampoos is zinc pyrithione which helps reduce itching and skin flakes by slowing down how fast skin layers shed and by helping to reduce oil production on the skin.
However, it sounds like you are experiencing a more severe form of dandruff known as seborrheic dermatitis. With seborrheic dermatitis, there is increased oil production on our skin which allows an overgrowth of a species of fungus that naturally lives on our body. This causes not only itchy, flaky skin but also redness and inflammation of the affected area. Skin flakes may have a yellowish appearance which is caused by an increased oil build up. Seborrheic dermatitis can affect oily skin areas beyond the scalp such as our face, eyebrows, ears, chest and upper back.
For anyone trying to picture what skin affected by seborrheic dermatitis might look like there is a good chance you have seen it before as it is a common condition in babies that is referred to as cradle cap. In babies, the condition is often self-limiting and goes away on its own but in adults, we generally require medicated shampoos to control the symptoms.
Selsun Blue has a large line of medicated shampoos, and some contain the medicinal ingredient selenium sulphide. Selenium sulphide helps to treat seborrheic dermatitis by slowing down how fast skin layers shed and by slowing down the growth of the fungus that causes redness and irritation.
Nizoral is another medicated shampoo used to treat seborrheic dermatitis that contains the medicinal ingredient ketoconazole. Ketoconazole is an anti-fungal medication that reduces fungal growth and has anti-inflammatory properties that help with itchy, flaking, redness and irritation.
There have been some small studies that have compared the effectiveness and tolerability of selenium sulphide versus ketoconazole. Ketoconazole appears to get symptoms under control faster and is less drying on the scalp and hair.
With either ingredient, you want to apply the product to damp hair and work it into a lather. Remember you are treating your scalp not just washing the strands of your hair so use the pads of your fingers to massage the lather into your skin. Leave on for five minutes to give time for the medicinal ingredient to be absorbed then rinse thoroughly. Repeat these steps for a second wash. This is done twice weekly for usually 2-4 weeks until symptoms clear, then you can use it once weekly or every other week to prevent recurrence.
On non-medicated shampoo days, be sure to use a gentle shampoo. You may notice certain shampoos and styling products cause further irritation of the affected area. You may also experience flare-ups that are triggered by sudden weather changes, stress, hormonal changes and illness. When this happens go back to using the shampoo twice weekly again.
If symptoms do not improve within six weeks of using a medicated shampoo, it’s time to book an appointment with your primary care provider. You could have a more severe case of seborrheic dermatitis that requires a prescription for an oral antifungal medication. You could also potentially have a completely different condition that presents with similar symptoms but is treated completely differently such as scalp psoriasis or eczema.
Erin Thompson (BSc, BScPharm) is a graduate of Dalhousie University and a community pharmacist practicing at Shoppers Drug Mart in Quispamsis N.B. Her opinions expressed in this newspaper are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to AskYourNBPharmacist@gmail.com.