Dandruff is harmless, but it can be embarrassing and inconvenient. It is basically flaking skin on the scalp that causes itching. Symptoms of this common complaint tend to worsen in dry winter conditions with lower humidity and may improve during the summer.
The most common underlying reason for dandruff is dry skin resulting from dry air. A frequent cause is seborrheic dermatitis, basically an oily scalp condition that may contain an abundance of yeast and leads to large white flakes or yellow scales from the uneven shedding and clumping of dead skin cells. Scalp eczema and psoriasis can also contribute to flaking and inflammation on the scalp that appear like dandruff, and cause patients’ scalps to itch.
Dandruff can also stem from the overgrowth of a yeast (malessezia) that is found on healthy scalps. It feeds on oils produced by your scalp, and excessive levels can cause itching and flaking.
Babies can be affected by a form of dandruff called cradle cap. Seen most often in newborns and during infancy, this condition involves a yellow or white scaling scalp and some crusting. It is harmless, and generally resolves within the baby’s first year.
Patients with darker skin tones are more likely to experience a more severe variant known as petaloid seborrheic dermatitis. It tends to occur around the scalp as a ring-shaped rash and may leave behind discoloration.
Shampooing more frequently is probably the most important method of dandruff control. This is because an oily scalp leads to accumulation and uneven shedding of dead skin cells, resulting in unsightly flakes. Depending on one’s hair type, wetting the scalp daily with use of shampoo 2 – 3 times per week, or use of regular shampoo daily may be sufficient to treat mild cases of dandruff. If that doesn’t work, there are several medicated dandruff treatment shampoos available over-the-counter.
Since medicinal ingredients vary from one product to another, you may have to experiment with different products, or rotate products to find out what works best for you and minimizes flaking.
Please note that the mention of a specific brand name does not constitute a recommendation for the product by the Canadian Dermatology Association.
Coal tar (e.g. Neutrogena T/Gel, Denorex) — This agent works by slowing skin cell turnover, the rate at which cells grow and are shed.
Salicylic acid (e.g. Sterex, Sebcur) — This exfoliating ingredient helps to loosen and slough off dead skin cells to prevent clumping and flaking.
Selenium sulphide (e.g. Selsun Blue, Head & Shoulders’ Clinical solution, Versel) — The sulphide slows skin cell turnover and may reduce fungus on the scalp.
Zinc pyrithione (Head & Shoulders, Dangard) — This agent acts in much the same way as selenium sulphide but is milder and results in less drying out of hair.
Ketoconazole (e.g. Nizoral) — This is an antifungal agent that reduces malessezia on the scalp.
Ciclopirox olamine (e.g. Loprox lotion, Stieprox) — This is another antifungal that reduces the amount of malessezia on the scalp. It’s available in prescription strength in both lotion and shampoo products.
Combination products (Vichy Dercos DS, Ducray Kelual DS, Kerastase Symbiose) – These shampoos have a combination of the ingredients listed above to address multiple pathways that can contribute to seborrheic dermatitis.
Dandruff can usually be effectively controlled with over-the-counter dandruff shampoos. However, if an itchy scalp persists despite using a dandruff-fighting shampoo for several weeks, or if you notice redness and swelling of the scalp, see a Certified Dermatologist for an assessment. You may need prescription-strength treatment.
- An estimated 50 per cent of North Americans have dandruff.
- Dandruff is most common in younger people and usually resolves by middle age, although it can persist later in life.
- More men have dandruff than women, possibly due to hormones that produce more active oil glands and an oilier scalp.
- Medical conditions and certain medications can trigger or worsen dandruff and its variant seborrheic dermatitis.