- Scabs on the scalp can be caused by inflamed hair follicles or inflamed skin.
- It can also be caused by infestations of lice or an infection called scalp ringworm.
- In rare cases, scabs that bleed and won't heal may be a sign of skin cancer.
- Visit Insider's Health Reference library for more advice.
Dealing with scabs on your scalp can be uncomfortable, itchy, and painful. It's important that you don't scratch or pick at them because doing so increases your risk of infection.
If you leave them alone, scalp scabs should heal on their own and are usually not a cause for concern.
However, if you're experiencing other symptoms in addition to scalp scabs, you may have an underlying medical condition that requires treatment.
Here are seven medical conditions that can cause scabs on the scalp, and how to treat them.
1. Seborrheic dermatitis
One of the most common causes for scalp scabs is an inflammatory skin condition called seborrheic dermatitis, says Susan Massick MD, board-certified dermatologist at The Ohio State University Wexner Medical Center.
While the condition may not directly cause traditional scabs, it causes scaly patches that people might identify as scabs. Furthermore, picking at these scales can result in wounds that turn into scabs.
Symptoms of seborrheic dermatitis include:
- Red, itchy scalp
- Scaly patches on scalp
- Flakes and dandruff
- Red scaly patches on eyebrows, sides of the nose, and chest.
The condition can worsen with stress and in cold and dry weather, Massick says.
How to treat it: There are over-the-counter antifungal shampoos with specific ingredients that can help fight itchiness and scaliness, says Calvin Williams, MD, FAAD, board-certified dermatologist at Essential Dermatology Group. He says to look out for the following ingredients:
- Ketoconazole
- Pyrithione zinc
- Coal tar
- Salicylic acid
In more severe cases, a doctor can prescribe you topical steroids in the form of leave-on solutions or shampoos,says Massick.
2. Psoriasis
While psoriasis is most commonly associated with areas like the elbows and knees, this chronic autoimmune disease can also cause thick scales on the scalp, Williams says. These scaly scabs are usually extremely itchy, and you may even experience hair loss from chronic scratching.
Other symptoms of psoriasis include:
- Patches of red skin covered in scales that are thick and silvery/white
- Dry cracked skin
- Burning sensations
How to treat it: Although there isn't a cure for psoriasis, a dermatologist can help you manage symptoms. Williams says treatment options include:
- Prescription topical steroid medications like Derma-Smoothe and Clobetasol can reduce the scales and itchiness. Some improvement can be seen as early as two weeks, but it can take a few months to see the full effects.
- Prescription oral medications specifically for psoriasis, such as Otezla help reduce scales and itching. However, it can take up to four months to see results.
- Injectable biologics which target the overactive parts of your immune system help reduce scales and itching. You may see improvement in as little as two weeks, but full effects will likely be seen around the three-month mark.
3. Contact dermatitis
Contact dermatitis occurs when the skin is exposed to an irritant or allergen. So, if your scalp comes into contact with a product or ingredient that you're sensitive or allergic to, you can experience inflamed, itchy, sore red patches, says Massick. Picking these patches can result in scabs.
Common causes are chemicals in shampoos or hair dyes such as:
So if your scalp is itchy after you've recently tried a new hair care product, contact dermatitis might be to blame.
How to treat it: When you stop using the product that's the culprit, the contact dermatitis should resolve itself. However, if you're experiencing a severe allergy, Massick says you may need to be prescribed a topical or oral steroid. Additionally, you should be sure to avoid the irritant in the future.
4. Folliculitis
When you have folliculitis of the scalp, the hair follicles become inflamed — typically because of a bacterial or fungal infection. This can result in inflamed acne-like bumps that are usually sore, tender, and scab when they're picked at or scratched, says Massick.
Causes of folliculitis include:
- Shaving, which can cause irritation
- A buildup of hair products
- Stress
Bacterial folliculitis is also possible, which is typically caused when moisture is on the scalp for an extended period of time, such as if you lay down and sleep directly after washing your hair without letting it dry, says Williams.
How to treat it: Folliculitis will usually go away in a few days. If it doesn't go away, see your doctor who may need to prescribe you prescription medicine.
However, you can prevent folliculitis by:
- Using new, sharp shavers when shaving your head and allowing hair to grow between shaves to avoid irritating your hair follicles
- Regularly washing your hair to prevent irritating product buildup
- Minimizing stress
- Letting your hair dry before bed
5. Scalp ringworm
A ringworm fungal infection can affect your hair follicles, resulting in very itchy scaly patches that may also cause hair loss and resulting round bald patches in the affected areas, says Massick. Picking at these patches can cause scabs.
This infection is most common in children, but adults can contract it, too. It's also highly contagious, so treatment is crucial.
How to treat it: Massick says treatment involves prescription antifungal medications, like Gris-Peg or Lamisil, that typically must be taken for at least six weeks.
6. Head lice
Lice are tiny insects that live on your scalp, lay eggs there, and bite your skin, causing symptoms like:
- Itchy scalp, especially at night when lice are most active.
- A subtle sensation that something is moving in your hair.
- If you scratch, it can lead to sores that scab over or may become infected and inflamed.
Similar to scalp ringworm, lice is most common in children, but it can also affect adults. The most common form of transmission is head-to-head contact with another person with lice. Sharing hair products like brushes or combs is another way to easily spread lice.
How to treat it: If you have lice, it's important to treat the condition ASAP to prevent spreading it to others and to prevent further lice from hatching. Massick says treatment includes:
- Removing the nits to keep them from hatching (typically done with a fine tooth nit comb).
- Applying over-the-counter topical treatments like shampoos containing permethrin (such as Nix).
- Using prescription topical or oral medications such as Ivermectin if the lice are resistant to OTC products.
7. Skin cancer
The most worrisome potential cause for scalp scabs is skin cancer, since skin cancer may present as lesions that bleed and won't heal, leaving scabs, says Williams. The main differentiator between skin cancer and the other potential causes is that the lesions will not heal.
Basal cell carcinoma is the most common form of skin cancer that causes difficult-to-heal sores, but squamous cell carcinoma and melanoma may show up this way, too.
The likelihood of a cancer like basal cell carcinoma being the culprit comes down to various risk factors such as:
- Being over 50 years old
- History of skin cancer
- UV exposure
How to treat it: A diagnosis by a dermatologist is necessary to determine a course of action.
"While skin cancer is by far not the most common reason to have a scab on the scalp, if you do have a scab of concern please consult your primary care doctor or a board-certified dermatologist," says Williams. Any lesion like this that won't heal should be checked out, as it may require a biopsy.
Some common skin cancer treatments include:
- Various types of surgery
- Chemotherapy
- Radiation therapy
Insider's takeaway
For most scalp scabs, the cause is not dangerous. However, Massick says you should definitely see a dermatologist if you're experiencing:
- Ongoing or recurrent painful and itchy sores
- Sores that don't heal within four to eight weeks
- Scalp pain and swelling.
As tempting as it may be, avoid picking at your scabs, since this can worsen the issue and potentially lead to infection. Once a doctor determines the root issue causing your scabs, you can take action to get relief.