An itchy scalp can be irritating and even painful, depending on the cause. There can be several triggers, such as various forms of dermatitis or reactions to certain hair products.

Experts consider it a common condition — one study found 25% of participants reported an itchy scalp.

It can be difficult to diagnose what causes an itchy scalp. Understanding the symptoms and treatments associated with the possible causes can help people better understand and address their symptoms.

Keep reading to learn more about the various triggers of an itchy scalp and how to treat them.

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The following are some of the most common factors that can lead to an itchy scalp:

Seborrheic dermatitis

The most common cause for an itchy scalp, seborrheic dermatitis (SD) is a condition that affects the parts of the body that are rich in oil-producing glands, such as the scalp, face, and back.

Dandruff

Researchers consider dandruff — when the scalp becomes so dry, it starts to itch and flake off — to be a mild form of SD.

Haircare practices

When people do not rinse out the shampoo when washing their hair, it can collect on the scalp and cause itching and flaking.

Head lice

Common among young children and their families, these parasitic insects live on human blood and are mainly spread through close personal contact.

Contact dermatitis

Some people have allergic reactions to hair products, such as black hair dye, causing itching and rashes on the skin.

Scabies

When human itch mites dig into the scalp, they can cause itching so severe it can stop a person from sleeping.

Hives

Outbreaks of itchy, often red and raised, bumps can develop anywhere on the body, including the scalp.

Ringworm

Despite the name, a fungus triggers this condition, which is also known as tinea capitis.

Scalp psoriasis

About 50% of people who have plaque psoriasis on their bodies also develop symptoms on their scalp.

Atopic dermatitis

This form of eczema affects the scalp, causing intense itching that can lead to infection.

The symptoms that accompany an itchy scalp can help individuals and healthcare providers determine the trigger. In turn, this can point the way towards likely treatment options.

Other symptoms that may come with an itchy scalp include:

  • Patches of thick, greasy scales on the scalp: These are frequently a sign of seborrheic dermatitis.
  • Flakes: When they appear in the hair or on clothing, these are signs of dandruff.
  • Small white nubs on the hair: These could be nits or the eggs of head lice. A medical professional will need to perform a visual examination to identify signs of lice.
  • Small raised bumps: These are often symptoms of scabies.
  • Hives: People with hives on their scalp often have them elsewhere on their bodies.
  • Red rash, pus-filled bumps, and hair loss: These can be signs of ringworm, especially if they all occur at the same time.
  • Silvery-white scales on a dry scalp with red patches: These symptoms suggest scalp psoriasis.
  • Difficulty sleeping: A possible sign of head lice or scabies, due to the severe itching.
  • Flaking skin on the upper back, chest, and face: Could be a sign of seborrheic dermatitis.
  • Dry, red scalp: Can be a sign of atopic dermatitis.

People should note that seborrheic dermatitis, scalp psoriasis, and atopic dermatitis can all have similar symptoms.

A person with these symptoms may need to work closely with their healthcare provider to find the best treatments for these conditions.

The best treatment for an itchy scalp depends on the cause:

  • Seborrheic dermatitis: Antifungal shampoos and anti-inflammatory medications can ease symptoms.
  • Allergies and dermatitis: A person can use hypoallergenic products and make sure they completely rinse the shampoo off their hair and scalp.
  • Dandruff: Over-the-counter (OTC) anti-dandruff shampoos can be effective.
  • Head lice: People can use OTC and prescription medication to treat head lice. Experts recommend treating everyone in the household, including close contacts, if one person is infected. People should also thoroughly clean all their clothes and household goods.
  • Scabies: The only way to remove scabies is with prescription medication and thorough cleaning of all clothes and household goods.
  • Hives: Hives tend to come and go on their own, but may respond to a change in diet, hair care practices, or both.
  • Ringworm: People can use prescription medication to treat ringworm.
  • Scalp psoriasis: Some people find OTC remedies can help, while others require medicated shampoos.
  • Atopic dermatitis: Experts recommend people keep their scalp moist and use corticosteroid lotions to control itching.

Generally, people can manage an itchy scalp at home. However, the condition can be difficult to self-treat in some cases, and an itchy scalp can also be a sign of an underlying health concern.

People should see a doctor if:

  • they are unable to find what causes their itchy scalp
  • hives on the scalp last longer than six weeks
  • significant hair loss develops
  • self-care practices do not reduce symptoms

Many different factors can cause the irritating, potentially embarrassing, and sometimes painful condition known as an itchy scalp.

They can be difficult to diagnose, and sometimes there might not be a clear trigger.

Many treatment options are available, ranging from OTC shampoos and lotions to prescription medications targeted for specific causes.