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.
The following are some of the most common factors that can lead to an itchy scalp:
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.
Researchers consider dandruff — when the scalp becomes so dry, it starts to itch and flake off — to be a mild form of SD.
When people do not rinse out the shampoo when washing their hair, it can collect on the scalp and cause itching and flaking.
Common among young children and their families, these parasitic insects live on human blood and are mainly spread through close personal contact.
Some people have allergic reactions to hair products, such as black hair dye, causing itching and rashes on the skin.
When human itch mites dig into the scalp, they can cause itching so severe it can stop a person from sleeping.
Outbreaks of itchy, often red and raised, bumps can develop anywhere on the body, including the scalp.
Despite the name, a fungus triggers this condition, which is also known as tinea capitis.
About 50% of people who have plaque psoriasis on their bodies also develop symptoms on their scalp.
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.