What Causes Itchy Scalp?

The skin on your scalp is thinner than on the rest of your body and may be more sensitive. Shampoos, conditioners and styling products contain many ingredients which can trigger allergic reactions, some of which may be severe. Harsh cleansers and chemical dyes are obvious suspects, but even “natural” and organic ingredients like plant-based oils, citrus extracts and fragrances may cause itching, burning, tender spots and/or a rash on the scalp and forehead. Try skipping a suspected product for a week or so and see if you get relief.

“This condition is known as contact dermatitis, and sometimes it can be tricky to determine exactly what is causing it,” says Alvin Coda, MD, a dermatologist at Scripps Clinic. “A board-certified dermatologist can do a patch test to help identify potential allergens, so you know which ingredients to avoid.”

This common condition causes itchy, dry, flaky scalp; look for telltale white flakes on your hair or clothing. Dandruff is not harmful or contagious, but it can be annoying. In most cases, a dandruff shampoo and scalp treatments can keep symptoms under control. Follow the directions for use carefully.

Severe dandruff is known as seborrheic dermatitis. If the problem persists, see a dermatologist.

Hair grows out of hair follicles in the skin. If a follicle develops a bacterial or fungal infection, it can become inflamed and irritated. This condition, called folliculitis, can spread to other follicles and often causes acne-like bumps that can be itchy, tender and painful. Mild folliculitis may clear up in a few days without special treatment, but more stubborn cases may require a prescription antibiotic or antifungal medication.

These tiny wingless bugs live on the head and neck and cause significant itching. Lice feed on human blood and lay their eggs at the base of the hair shaft. They travel by crawling and can be highly contagious, especially when people are in close contact or share towels, combs, pillows and other items that touch the head. Lice are not spread by pets, nor do they indicate poor personal hygiene.

Head lice or eggs are often visible upon close inspection of the scalp. If you do find lice, everyone in your household will need to be treated with an over-the-counter (OTC) or prescription medication shampoo formulated especially to kill the bugs; follow directions exactly and repeat the treatment if needed. You’ll also need to wash all bedding, towels and clothing used by infected family members in hot water and dry on high heat, and soak combs and brushes in very hot water for at least 10 minutes.

“You’ll have to keep checking the scalp every day for a week or so to make sure the lice are gone,” says Dr. Coda. “Getting rid of lice can be a challenge, so don’t hesitate to call your doctor if you have questions or the treatment doesn’t seem to be working.”

Psoriasis is a chronic autoimmune disease that causes red, scaly patches on the skin. About half of people who have it will develop itchy patches on their scalp as well. Over-the-counter products for scalp psoriasis can provide relief, but if they aren’t effective, a dermatologist can prescribe stronger treatments.

“Many factors can irritate the scalp, so if you’re not sure what is causing the problem, make an appointment with a dermatologist,” says Dr. Coda. “We can diagnose the problem and get you on the right treatment plan.”

Ever had a car accident or traumatic neck injury? Ever notice there are both painful/burning areas in addition to the itch? Nerve related itch is a little known but pervasive source of itch. Arthritis and degenerative disk disease in the neck distributes all the sensations on a large portion of the scalp and creates a common and uncomfortable feeling on the scalp that is commonly interpreted as itch.

X-rays can identify structural issues that might be addressed by physical therapy or treated with oral nerve-calming medications.

Sun damage accumulates over our entire lives, leading to abnormal growths and sun spots. One growth of concern to consider in your itchy scalp is an actinic keratosis, a scaly/rough spot that can have itching, discomfort, or no symptoms at all. These lesions are generally considered pre-cancerous in nature and should be treated to minimize the risk of developing squamous cell skin cancers.

These lesions can be treated with liquid nitrogen, chemotherapy creams and immune system stimulating creams.