What Causes Dandruff?

September 19, 2023

Dandruff is a scalp condition that leads to flaking of the skin. Many affect individuals also experience itchiness, but itchiness isn't required for someone to have dandruff. The exact cause of dandruff isn't currently known, though several conditions have been linked to the presence of dandruff. The ways these conditions lead to dandruff vary. Some cause the skin to flake due to dryness, while others may cause texture problems and flaking because of an immune response. Though dandruff isn't caused by poor hygiene, there is a stigma surrounding it. Some dandruff might be more easily visible if an affected individual doesn't brush or wash their hair often. It's common for dandruff to cause embarrassment, and it might be difficult to treat, but there are options.

Malassezia

Malassezia, a type of fungus that can contribute to dandruff, is a genus that contains fourteen different species of fungi similar to yeast. In fact, individuals who have sensitivities to yeast also have higher chances of developing dandruff. This indicates yeast and yeast-like fungi might have a larger role in dandruff than previously thought. If patients have a yeast sensitivity, it may be contributing to their dandruff. When individuals have yeast-related dandruff, they often notice the flakes are at their worst during the winter. Warmer summer weather leads to less flaking. Researchers aren't sure why this is, but one theory is the UVA light the sun emits helps counteract the yeast. Since sunlight is more direct and the days are longer during the summer, there's greater UVA exposure. Malassezia fungus can manifest clinically in a variety of ways on the scalp or other parts of the skin. It might be part of a benign skin condition, or it might be a result of immune system issues.

Dry Skin

Dry skin makes an individual more likely to develop dandruff. If an individual's skin is only dry during certain seasons or at certain times, they might notice dandruff appears more heavily then. For example, dry conditions and cold winter air are more likely to cause dryness and chapping of the skin. It's also common for skin to dry out and flake when an individual is in an overheated room. When dandruff is caused by dry skin rather than another underlying condition, the flakes tend to be small and non-oily. By contrast, dandruff caused by fungi or other skin conditions tends to be oily. Dry skin can sometimes be remedied by using certain shampoos and skincare products that help with moisture. However, patients should make sure they're formulated without potentially harmful chemicals. If individuals think an underlying skin condition might be causing the dryness, they should have a consultation with a dermatologist. In addition, getting a humidifier for the home might help if their dry skin is caused by very dry conditions. Humidifiers release moisture into the air, which can help individuals in hot climates, like deserts.

Sensitivity To Hair Products

Dandruff and flaking can often be caused by sensitivity to hair products. These products damage the scalp and cause an immune reaction that can lead to burning, itching, or stinging. If individuals notice their scalp and hair have significant dandruff after switching hair products, it's a telltale sign of sensitivity. Research indicates styling products and heat don't tend to cause dandruff by themselves, though they can lead to scalp damage that aggravates an already-existing dandruff condition. If the scalp becomes damaged due to burns, chemical irritation, or an allergic reaction, there may be the same dry flakes caused by dry skin. These flakes will typically go away after individuals stop using the product that triggered the reaction and allow their scalp to heal. The dry flakes are technically not considered dandruff from a medical standpoint, but most patients don't know enough about them to differentiate. According to dermatologists, actual dandruff is only the oily and large flakes caused by fungus.

Not Shampooing Enough

Some researchers believe not shampooing enough can cause dandruff and flaking, or that it can at least contribute to issues that already exist. At the same time, shampooing too much is likely to increase an individual's chances of developing dandruff. Many individuals shampoo their hair every day when they shower. Unfortunately, daily shampooing isn't good for the hair or scalp. Experts recommend shampooing every two to three days, though individuals with curly hair textures may not need to shampoo or condition their hair for even longer. When individuals shampoo too frequently, they strip their hair of its natural oils, which causes the scalp to create more oil in response. It also causes general scalp irritation, which can lead to itchiness and flaking. This is especially true if an individual's shampoo contains harsh chemical irritants. If individuals shampoo every day, they should try switching to every other day instead and see if there's any improvement. Their hair might be a little greasier at first, but it should stabilize once their glands stop overproducing oil.

Seborrheic Dermatitis

Seborrheic dermatitis, also called seborrheic psoriasis and seborrheic eczema, is a skin condition that mainly affects the scalp and leads to dandruff, reddened skin, and scaling patches. Some patients also experience symptoms on oily parts of the body including the chest, eyelids, ears, eyebrows, sides of the nose, and face. The severity of the condition and places it manifests vary from case to case. Sometimes the condition resolves on its own and doesn't require treatment. However, some patients do need multiple treatments to make the issue go away, and they may experience recurrences. It helps to cleanse daily with a gentle soap to reduce the buildup of dead skin and oil. If patients have eczema or psoriasis on other parts of the body, it may affect their scalp and lead to dandruff as well. A dermatologist can help determine how to treat it.

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