An itchy scalp has many possible causes, including your shampoo, hair dyes, diabetes and dermatitis.

“Itchy scalps are usually caused by either dandruff or allergies,” says Dr. Joel Schlessinger, MD, board certified dermatologist and cosmetic surgeon with a private practice in Omaha, NE.

“Dandruff is often caused by a yeast overgrowth and can be coincidental with other dry, scaly issues such as facial dermatitis (seborrheic dermatitis) or even a slightly red rash on the chest area.”

The itch from seborrheic dermatitis may also have a mildly stinging component to it.

“If itchy scalp is due to ingredients in shampoos, there is a line, Free and Clear, that contains very few of the offensive ingredients (LovelySkin.com/Freeandclear). This line also has a conditioner and hair spray.

“Without having patch testing done, it is very difficult to determine whether this is allergy or, if it is an allergy, which ingredient is the culprit.

“Hair dyes are a very common cause of allergies and it is also important to realize that permanents can cause a variety of allergic or sensitivity reactions.

“If you suffer from itchy scalp it is best to seek treatment first from a dermatologist before undergoing coloring or other hair treatments.

“Generally, in my patients an exam can determine whether it appears allergic or dandruff related, but sometimes it is unclear initially.  Treatments such as medications will often help to clarify the cause.

“If there isn’t any rash present, that is sometimes due to nerve related issues and that is an entirely different medical treatment process.

“Additionally, if there are sores or other situations such as lice or infections, your treatments may be quite different, but this is something that should be evaluated at the time of the appointment.

“Lastly, as far as other medical causes, while there are definitely some issues such as diabetes that can cause scalp irritation and infection, the root (no pun intended) of the problem is usually treated alongside the condition by your internist or family doctor.”

Additional causes of an itchy scalp:

Do you use minoxidil (Rogaine)? The insert actually states that a possible side effect is an itchy scalp.

Aggressive hair brushing can cause the scalp to become irritated, and hence, itchy. The aggressiveness is in the form of pressing the bristles hard into the scalp.

Or, simply over-brushing (spending too much time doing this) can cause the irritation. Pressing a comb too hard against the scalp can do the same.

Lastly, not washing your hair enough can cause the scalp to itch—from accumulated grime.

Dr. Schlessinger, founder of LovelySkin.com, has 25+ years of experience treating many skin conditions including melanoma. He’s founder of the Advanced Skin Research Center, a clinical facility that investigates new medications and treatments.
Lorra Garrick has been covering medical, fitness and personal/cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.