If you have an itchy scalp or flakes in your hair, you may be tempted to just reach for the nearest dandruff shampoo. Before you do, read on to find out common misconceptions about the irritating condition — and get experts' advice on dealing with it. Dandruff is not caused by dryness. If the skin on your body or face becomes scaly or itchy, your first instinct is probably to reach for a moisturizer. When your scalp is flaky, though, it’s usually the result of too much oil rather than too little. “It’s a common misconception that dandruff is caused by dryness; in reality, it’s usually due to an overgrowth of a harmless yeast,” explains Jessica Wu, M.D., a Los Angeles dermatologist and assistant clinical professor of dermatology at the University of Southern California Medical School. “In some people, the yeast starts to feed on the excess oil and dead skin cells on the scalp, causing the skin cells to shed more frequently and clump into flakes.” You should wash your hair more often. Normally, dermatologists warn against shampooing your hair every day, the concern being that you’ll strip the scalp and hair of natural oils and cause irritation. Dandruff poses the opposite problem. “Not shampooing enough will only make your dandruff worse — it causes more oil and dead skin cells to accumulate on your scalp, which the yeast and fungi just continue to feed on,” warns Beverly Hills dermatologist Stuart H. Kaplan, M.D. To rid your scalp of dandruff, you need to clean out all the gunk, which a regular shampoo won’t do. Dr. Kaplan recommends a medicated dandruff shampoo (which you can find at drugstores) every day, one that contains ketoconazole, selenium sulfide, or zinc. If your hair is coarse, though, and you’re concerned that daily shampooing will make it more brittle, you may want to use a dandruff conditioner too. A flaky, itchy scalp does not always mean dandruff. If you don’t see any improvement after washing for a week or two with a medicated shampoo, there might be another culprit. “You could have psoriasis or a skin inflammation. Some hair treatments and certain products with harsh chemicals can create an allergic reaction or sensitivity that dries out your scalp,” says cosmetic chemist Ni'Kita Wilson, vice president of research and innovation at Englewood Lab. So then, in this case, the flakes would have nothing to do with dandruff. “When dandruff shampoos aren’t cutting it, you’ll want to see a dermatologist, who’ll be able to diagnose your specific condition and prescribe the right remedy to treat it.” You can get dandruff on your face and body too. Those oily flakes are not necessarily restricted to your scalp. It’s not uncommon for women to discover dandruff flakes in their eyebrows, around their ears, and along the sides of their nose — anywhere a lot of oil is produced. Usually such scaly patches occur in addition to a flaky scalp — if you have these extra skin-shedding spots, use your dandruff shampoo to gently clean them when you wash your hair. Dandruff can’t be cured, but it can be controlled. Unfortunately, if you’re prone to dandruff, it’s most likely a problem that will continue to recur. Still, you don’t have to wait for flakes to make an appearance to start treating them — you can take preemptive action to avoid flare-ups. “Diets high in saturated and trans fats cause your sebaceous glands to produce more oil, which makes dandruff worse,” explains Kaplan. “Avoiding these fats, as well as incorporating varied fruits and veggies that contain zinc and B vitamins, will help keep the flakes at bay.” You may also want to consider taking a probiotic — any of a group of beneficial bacteria that can be found in yogurt or can be taken as a supplement — to combat the overgrowth of yeast. Source
there are many causes of Dandruff.......e.g. being in Sunlight for a long time,keeping your scalp dry (without oil etc),not taking proper diets.....& so on