20 reasons for your itchy scalp (besides head lice)

There it is again – that tingling feeling up top. How good would it feel to just reach up and rake your fingernails across that scalp of yours a few times? But you don’t dare because once you start, it’s so hard to stop. As Harvard-trained dermatologist, Dr Khalil A. Khatri admits, “Once you get into the “itch-scratch-itch cycle, it’s difficult to get out of it.” It’s vexing when your head itches not only because it’s so hard not to scratch, but also because it’s usually a symptom of something else. So what does it mean when your head itches? Fear not. There are many reasons for your itchy scalp, we were assured by Dana R Brewer, a physician’s assistant with a specialty in dermatology, and most of them are a cinch to treat.

OK, let’s just get this one out of the way. Let’s say you’ve got school-age kids, and you find yourself asking, “Why does my scalp itch?” Is there any way you’re not going to wonder if it’s head lice? Head lice are tiny bugs that attach themselves to body hair, according to the Centers for Disease Control and Prevention. “Head lice can be seen in the form of eggs, aka nits, along the hair shaft,” explains associate clinical professor of dermatology Dr Rhonda Q. Klein. Although the nits can be confused with dandruff, when you see adult lice moving around your head, that’s unmistakable. “You can use physical methods to remove the lice,” Dr Klein says, “and you can try natural lice shampoos and natural lice removers, “although what you’ll probably end up needing to eradicate a lice infestation is an actual “insecticide like pyrethrin and permethrin,” depending on resistance patterns in your area. “Shaving the head is also an easy solution for boys.”

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If it’s not lice, you might wish it were when you learn about scabies, which according to Dr Khatri can cause itching not just on the scalp but also on the entire body. Scabies on the scalp isn’t common, and it usually affects those with compromised immune systems.

Scabies are an infestation of the “human itch mite” (aka sarcoptes scabiei var. hominis). The scabies mites burrow into the upper layer of the skin, where they live and deposit their eggs, according to the CDC. The microscopic scabies mite almost always gets passed along by direct, prolonged, skin-to-skin contact with a person who already is infested. Scabies in adults frequently is sexually acquired, although it can also be spread without sexual contact in crowded conditions, including households, nursing homes, extended-care facilities, child-care facilities and prisons.

So, let’s say you’ve ruled out head lice and scabies. If you’re still asking “why does my scalp itch,” then dandruff is your most likely culprit. Or more specifically, seborrheic dermatitis, which is considered a severe form of dandruff caused by an overreaction the body has to normal yeast that lives on the skin, according to dermatologist, Dr Jennifer Haley. Dandruff affects about 40 per cent of people and tends to come and go during one’s lifetime. “Weather changes, stress and increased sugar in the diet can bring it out.”

Over-the-counter remedies include products containing the active ingredient, salicylic acid (such as Neutrogena T/Sal Shampoo) and products containing antifungals such as ketoconazole or selenium sulfide (Selsun Blue Shampoo contains the latter). Natural remedies for dandruff include tea tree oil. And a product called Scalpicin can help decrease itching, Dr Haley advises. If over-the-counter remedies do not resolve the issue, then see a board-certified dermatologist, who can not only prescribe steroidal anti-inflammatories but also determine if some other condition is causing your itchy scalp symptoms.

If you recently coloured your hair, it’s possible that you’re experiencing an allergy to the dye. This is true even if you’ve used the product before without incident. “If the hair colour is temporary or semi-permanent it can be washed out,” explains dermatologist, Dr Joshua Ziechner, “but if it’s a permanent dye, that presents a more challenging situation, although there are products on the market that can remove permanent dye altogether.”

“People can have a reaction to anything they put on their scalp – from shampoo to hair dye to Rogaine,” points out Dr Haley. “And don’t forget about those hair-smoothing keratin treatments, adds Dr Klein.

To pinpoint the culprit product or ingredient suggests dermatologist, Dr Tsippora Shainhouse, try using one product at a time for a week at a time, rather than combining many at the same time.” And then while your scalp is healing, choose only gentle and sensitive skin formulations.

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An itchy scalp can also be caused by inflammatory skin conditions such as eczema (aka atopic dermatitis, especially in babies, eczema can present on the scalp) and psoriasis (which is more likely to appear on the scalp of an adult). Dr Zeichner explains that these conditions arise when your immune system gets “angry” at your skin, leading to red, flaky, itchy patches.

Psoriasis looks similar to dandruff but is usually thicker and red, notes dermatologist, Dr Esta Kronberg, but it can be treated the same way dandruff is treated. For both eczema and psoriasis, Dr Klein recommends topical steroids, vitamin D analogues (calcipotriene), coal tar, salicylic acid, excimer laser, phototherapy, and immunomodulatory agents for severe cases.

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It’s possible that your itchy scalp is nothing more than a sunburn, Dr Shainhouse suggests. If you’ve been out all day and forgot to wear a hat, think sunburn first, and get some relief with a cool shower and some hydrocortisone cream (available over the counter).

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The winter months can come with dry air, whether cold outdoor air or heated indoor air. The dryness strips the scalp of its protective oils, according to Dr Shainhouse, who suggests that if your head becomes itchy in winter, your first plan of action could be to try a moisturising hair conditioner or a once-per-week scalp and hair mask.

“When you don’t wash your hair often enough, natural oils, dirt and product residue build up on your roots and scalp, causing you to itch and scratch,” says Dr Shainhouse. “Scalp skin is similar to face skin and need to be washed.” Dr Shainhouse recommends washing every other day. If you think your strands are too dry for frequent washing, flip your head into the sink and focus on the roots only. Scrub your scalp and roots with shampoo and be sure that it lathers well before rinsing in order to dissolve the excess oils and debris.

Likewise, your scalp could itch because you simply skipped your shower after a “super-soaker spin class,” Dr Shainhouse suggests. “When the sweat on your scalp dries, it can irritate the skin, leaving it feeling itchy.” The simple solution: wash your hair every time you sweat/work out.

Rosacea classically presents as red flush and (sometimes) pimples on the face. Rosacea may flare in the heat, after eating spicy, hot or caffeinated foods and drinks, or as a result of emotional stress, according to the American Academy of Dermatology. While it normally affects the cheeks, chin and nose, says Dr Shainhouse, it can potentially affect the scalp, causing an itchy or burning or stinging sensation. If you think that you might have rosacea, see your dermatologist to figure out the best management plan.

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