What could be causing your itchy scalp?

An itchy scalp can be distracting, disruptive, and even embarrassing. To start down the path to relief, it helps to understand what could be causing your itchy scalp.

Common causes of an itchy scalp

There are a number of different reasons your scalp might be itchy, from simple dry skin to infection, irritation, or infestation.

Dry scalp

An itchy scalp often results from something benign, like dry skin. This is especially common in the winter and in cold, dry climates. Dry scalp treatment can involve taking a break from certain shampoos or other hair products, which might be irritating your scalp by stripping away too much of the natural oils your scalp usually produces. Look for shampoos labeled "moisturizing" or "gentle," which might be less irritating.

Dandruff and seborrheic dermatitis

An itchy scalp that also feels dry and produces white flakes on your hair or clothing could be dandruff, which is considered a mild form of seborrheic dermatitis. Seborrheic dermatitis is an inflammatory condition that can occur anywhere on the body that produces oil, such as the scalp.

Over-the-counter dandruff shampoos may help relieve the itchiness if you have a mild case. If that doesn't clear up your symptoms, your doctor might give you a prescription-strength dandruff treatment shampoo, antifungal creams or foams, or topical corticosteroids to apply to your scalp.

Allergic reactions and sensitivities

Shampoo or other hair products can contain irritants or allergens that cause itchiness and a rash. This is more common in people who dye their hair. The only solution if you're allergic or sensitive to something on your scalp is stop using the product triggering your symptoms.

If you're having trouble narrowing down the problem product, keep a symptom journal and talk to your primary care provider or a dermatologist. They can help you figure out which hair products you might need to avoid.

Atopic dermatitis

Atopic dermatitis is a type of eczema that can result in red, itchy, scaly skin, including on your scalp. Washing your hair too often in hot water can make your symptoms worse, as can scrubbing your hair and scalp too aggressively. Your doctor will likely prescribe a corticosteroid cream or other topical treatment to apply directly on your scalp.

Fungal infection (tinea capitis)

If your scalp is itchy and you also notice pus-filled bumps and hair loss, you could have a type of fungal infection called tinea capitis, also known as scalp ringworm. This infection is known for its intense itch. The fungi that cause scalp ringworm thrive in warm, damp areas like a sweaty scalp, especially if you don't wash your hair often. You'll need to take prescription oral medication for up to two months to clear the infection, so see your doctor as soon as possible. Medicated shampoo may help address symptoms while you wait for the oral meds to kick in.

Head lice

Head lice are tiny insects that live in human hair. The most common sign you may have a head lice infestation is an itchy scalp, caused by the bites of the lice. Despite the stigma surrounding lice, personal hygiene is not to blame. Lice spread easily from person to person. Getting rid of head lice is a process that requires using medicated shampoos or lotions, and carefully, repeatedly combing the lice and eggs out of your hair for at least two weeks.

Hives

Notice a red, itchy rash on your scalp that comes on quickly and disappears shortly after? You might have hives, a reaction to food, medicine, allergens, stress, sweat, or another trigger. If your hives don't disappear on their own, you can try taking an oral antihistamine to calm the itchiness. If your hives last a long time, your doctor might prescribe an oral medication to treat your symptoms.

Scalp psoriasis

Psoriasis is an autoimmune disease that causes painful, itchy, and sometimes silvery, scaly patches of skin known as plaques. About half of people with psoriasis develop plaques on their scalp, which can be confused with dandruff. Your doctor might recommend treatment with over-the-counter salicylic acid, psoriasis shampoos, steroid creams, light therapy, or some combination of these treatments.

When to see a doctor for an itchy scalp

With so many possible causes, it's not always easy to determine what's causing your itchy scalp. Discuss your symptoms with your primary care doctor or a dermatologist if you're having trouble determining what's making you scratch.

Also talk to a doctor if over-the-counter treatments or home remedies don't help, or if the itch gets worse or becomes painful.