The mainstay of treatment for dandruff is a topical antifungal shampoo. Many of the shampoos that fight yeast in seborrheic dermatitis also help scalp psoriasis, possibly because the antifungal agents are also inherently anti-inflammatory. There are so many over the counter products– I hope this summary helps guide your search for your go-to dandruff shampoo. It might take some trial and error.
One of the most common prescriptions I send is for ketoconazole 2% shampoo, which is extremely effective, well tolerated, and safe to use. It is in the category of topical “azoles” which studies have shown are the best treatment for seborrheic dermatitis. Just the other day, the pharmacy at my hospital ran out of it, which I believe was single-handedly my fault. Luckily for you, Nizoral shampoo is a 1% ketoconazole formulation that is available over the counter for only about $15/bottle. Studies have shown that it is slightly less effective than the 2% formulation for severe seborrheic dermatitis; however, I have found that it works extremely well in a pinch.
If, after a week or two, you are not getting enough relief from the ketoconazole shampoo, you can switch completely to a different shampoo or fold in another anti-dandruff shampoo with a different active ingredient to use on the off days.
Selenium sulfide is my next favorite choice — it both decreases yeast burden and decreases the rate of skin cell turnover. Prescription strength is 2.5% selenium sulfide, but Selsun blue “max strength” shampoo has 1% selenium sulfide as its active ingredient. Many of my patients find it to be extremely effective.
Zinc pyrithione may be slightly less effective than selenium sulfide shampoo. My preferred brand of zinc-containing shampoo is Free and Clear, which contains 2% zinc pyrithione and has a gentle, fragrance-free formulation. Head and Shoulders is the most recognizable brand with zinc as an active ingredient; however, it’s not my favorite choice as it contains other potentially irritating ingredients.
Salicylic acid is a gentle anti-inflammatory agent that’s actually from the same family as aspirin. We use it for many skin conditions to help soften flaky, scaly skin. Salicylic acid is an excellent option — there is a product from Jason’s called dandruff relief treatment shampoo that contains salicylic acid in addition to many botanical ingredients and is beloved by many dandruff sufferers.
Speaking of botanicals, tea tree oil has been shown to be effective in treating dandruff (41% v. 11% improvement in patients using placebo). Note that tea tree oil may cause allergic contact dermatitis in up to 2.5% of people (refresher: allergic contact dermatitis is a type of skin allergy). In the study of using tea tree oil to treat dandruff, they did not observe this side effect but only followed the patients for four weeks. My take on this issue is that there are other more effective options that are less likely to irritate your skin; however, for those who prefer a more “natural” active ingredient, tea tree oil is an option. But stop if you notice it’s not getting better or you develop a new rash – it may be contact dermatitis.