An itchy scalp is not only uncomfortable - it can be embarrassing. Who wants to repeatedly scratch their head in public? Scalp itching can have a variety of causes, but the most common are seborrheic dermatitis, ringworm, head lice and psoriasis.
The majority of people with seborrheic dermatitis have scalp itching, scalp flaking and crusting. In some cases, skin on the face and upper body are also involved. No knows exactly what causes this scalp condition, but a fungus called Malassezia plays a role. People with seborrheic dermatitis seem to mount an inflammatory response against this fungus leading to scalp crusting, itching and flaking. Genetics also play a role in who develops seborrheic dermatitis since it’s more common in some families. Seborrheic dermatitis can be difficult to distinguish from psoriasis, another cause of an itchy scalp.
In terms of treatment, good scalp hygiene is important. Shampoos that contain pyrithone zinc or selenium sulfide are effective for treating this scalp condition. Salicylic acid is another ingredient in some dandruff shampoos that helps to loosen scales so they can be removed. When shampooing, leave the shampoo in contact with the scalp for 5 to 10 minutes before rinsing.
Shampoos that contain tea tree oil also help some people with this scalp problem. In more severe cases, doctors recommend shampoos that contain the anti-fungal ingredient ketoconazole and hydrocortisone cream or foam to treat itching. Diet may also play a role. There’s some evidence that diets higher omega-3 fatty acids found in fatty fish improve this scalp problem.
An itchy scalp can also be a symptom of ringworm, a condition caused by a fungus. Other signs and symptoms of ringworm are round scaly red patches on the scalp and patchy hair loss. This condition is more common in children and easily spreads from child to child and from child to adults. To make the diagnosis, doctors take a scraping of the affected area. Then they treat it with potassium hydroxide and look at it under the microscopic to look for the characteristic fungi.
Shampooing with medicated shampoo that contains 2.5 percent selenium sulfide is effective for treating mild cases of scalp ringworm. A medicated shampoo can be used up to three times a week. Shampoos that contain the anti-fungal medications ketoconazole or ciclopirox are alternatives to sodium sulfide shampoo. In some cases, shampoos aren’t enough to cure ringworm, and a doctor may prescribe oral antifungal medications.
Head lice, a condition more common in children, can cause scalp itching and irritation. When it’s the cause of scalp itching, you’ll usually see nits (lice eggs) attached to hair strands. Be careful! It’s easy for these lice to spread from person to person, especially when kids play together or share personal belongings like combs and brushes.
To treat head lice, a special nit comb can be used to physically remove lice and lice eggs from hair followed by cleansing with shampoos that contain permethrin or pyrethrin. If this isn’t effective, a doctor may prescribe a prescription shampoo or lotion called Lindane to kill the lice. Another medication called Malathion is an option for children age 6 or older. Unfortunately, prescription treatments for lice can have serious side effects including seizures, so they should be used with caution. It’s important to wash any personal items that came into contact with a child or adult with head lice to avoid spreading lice.
Psoriasis is a chronic skin condition that affects the skin or scalp. It seems to be caused by immune cells attacking normal skin cells. This causes them to overgrow and form scaly patches that are often silver in color. When it affects the scalp, it causes scalp itching, irritation and tenderness. People who have scalp psoriasis usually also have skin involvement too. A variety of factors can trigger the symptoms including changes in temperature, certain personal care products, infections, stress and alcohol.
...scalp itching may be due to an allergic reaction to a hair care product.
Shampoos formulated with ketoconazole, an anti-fungal medication, or coal tar are helpful for treating scalp psoriasis. For scalp itching, doctors sometimes prescribe shampoos or foams that contain hydrocortisone to reduce scalp irritation and inflammation. Shampoos that contain salicylic acid help to reduce scaling and crusting. Other treatments for severe cases of psoriasis include phototherapy, retinoids, vitamin D analogues and prescription medications that suppress the body’s immune response. Some of these medications can have serious side effects. Eating a diet rich in omega-3 fatty acids, limiting alcohol consumption and reducing stress may also help.
Other Causes of Itchy Scalp
In some cases, scalp itching may be due to an allergic reaction to a hair care product. Some people are sensitive to ingredients in hair dye and experience severe itching after using them. Some medical conditions including diabetes, lupus or underactive thyroid can also cause scalp irritation and itching. That’s why it’s important to find out what’s causing an itchy scalp.
The Bottom Line?
There are a variety of treatments for an itchy scalp, but treatments vary depending on the diagnosis. That’s why it’s important to find out what’s causing it. Fortunately, there are shampoos and other treatments that can help in many cases.