Bumps on the scalp can occur due to various reasons – inflammation, autoimmune processes, infection, allergic reaction, and rarely, due to cancerous growth.
Most scalp bumps are not alarming, however, early diagnosis and treatment can give quick relief. In addition, severe infections and skin cancers need immediate medical attention.
Below you will find 16 causes of bumps on the scalp, with pictures and treatments.
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1. Folliculitis
Pimple-like bumps on the scalp that hurt may be due to folliculitis. Folliculitis is the inflammation and/or infection of the hair follicles. It can lead to itchy and painful bumps on the scalp. If the infection gets deeper into the hair follicle, it may form a boil.
Cause and types
Folliculitis is of various types and the most common type is bacterial folliculitis. It is usually caused by Staphylococcus aureus.
Another type is Malassezia folliculitis which is caused by a yeast that is normally present on the skin called Malassezia.
Certain factors can increase one’s chance of getting folliculitis. These include any scalp injury, heavy sweating, suppressed immune system, or medical conditions like diabetes.
Treatment
- Avoid wearing tight hats or headbands.
- Take a break from shaving your scalp.
- Keep your scalp clean with regular shampooing.
- A warm compress may relieve itching.
- Mild cases of folliculitis may resolve on their own.
- For bacterial folliculitis, antibacterial shampoos may be helpful. In some cases, your doctor may prescribe topical antibiotics like mupirocin or oral antibiotics.
- Malassezia folliculitis can be improved by the use of dandruff shampoos with antifungal ingredients like zinc pyrithione. In some cases, topical or oral antifungals may be prescribed.
2. Scalp acne
Scalp acne refers to acne spots on the scalp and along the hairline. Just like acne anywhere else on the body, the blocking of pores with oils and dead skin cells, inflammation, and proliferation of acne-causing bacteria can cause acne spots or bumps on the scalp.
In some cases, haircare products can cause acne. This is called acne cosmetica.
The acne skin lesions can be:
- Non-inflammatory which includes open and closed comedones.
- Inflammatory which includes red bumps – papules, pustules, cysts, or nodules.
Treatment
- Regularly shampoo your scalp.
- Use shampoos based on salicylic acid or sulfur.
- Wash your hair after excessive sweating or exercise.
- Take a close look at your hair care products and avoid using excessively oily hair care products.
- If you don’t see any improvement, it’s best to see a doctor for topical or oral antibiotics or other medications.
3. Atopic dermatitis
Atopic dermatitis is the most common type of eczema. It can lead to redness, spots or bumps, dryness, oozing, and cracking of the skin.
It is often associated with itching which can lead to scalp sores and infection. It is commonly seen in children although it can occur at any age.
Redness and bumps are more often seen in small children while in adults it often presents with dryness and thickening of skin.
Cause
The exact cause is not known. It is associated with genetics, skin barrier dysfunction, altered skin microbiome, or environmental factors.
Treatment
- Avoid the use of very hot water while taking a bath.
- Gentle scalp care with shampoos containing moisturizing ingredients and oatmeal extract may relieve dryness and itching.
- In some cases, your doctor may prescribe topical steroids, calcineurin inhibitors, or other topicals.
4. Hives
Itchy red or skin-colored bumps on the scalp can be due to hives (urticaria). These bumps are oval, round, or irregular in shape. In some cases, multiple bumps can come together to form a larger spot. They usually last for a short duration.
Cause
Hives often occur due to the release of histamine from our immune cells. This can occur in response to certain medications, foods, pollen, and some infections.
Treatment
Hives usually don’t require treatment. In some cases, your doctor may prescribe steroids or antihistamines. One should avoid what initially triggered the reaction.
5. Contact dermatitis
Contact dermatitis can lead to itchy red bumps on the scalp.
Cause
This can occur if the scalp comes in contact with an allergen or irritant. These include dyes, fragrances, essential oils, harsh surfactants, jewelry, molds, pollens, etc.
These can be found in the environment or in hair products like shampoos, hair styling products, or hair dyes.
Treatment
It is essential to avoid further contact with the product which caused the reaction. Cool compress, antihistamines, and topical steroids may help in decreasing the symptoms.
6. Scalp psoriasis
Scaly bumps on the scalp can be due to psoriasis which is a chronic inflammatory skin condition that affects the scalp very commonly.
Plaque psoriasis is the most common type which presents with red raised areas on the skin called plaques, covered with silvery scales. Removing the scales or scratching can lead to scalp scabs and sores.
Cause
The exact cause is not known. It is associated with genetic factors, the immune system, and environmental factors.
Treatment
Scalp psoriasis is usually treated with shampoos or topicals containing coal tar or salicylic acid. In some cases, your doctor may prescribe topical steroids, immunosuppressants, vitamin D or A derivatives, and other treatment options.
7. Head lice
Head lice infestation is commonly seen in small children. These are small insects that live on the scalp. Head lice can lead to itchy bumps on the scalp and back of the neck. Scratching can lead to scalp sores and infections.
The adult lice or their eggs can be spotted on the hair. One may also feel a sensation of something crawling on the scalp.
Head lice don’t fly, but can crawl. One can acquire by direct head-to-head contact or items that come in contact with the head of someone with lice.
Treatment
It can be treated with over-the-counter available shampoos or topicals with ingredients like permethrin which can get rid of head lice. In addition, a fine-toothed comb is useful for removing them.
If OTC treatment options don’t work, your doctor may prescribe:
- Malathion lotion
- Benzyl alcohol lotion
- Spinosad suspension
- Oral ivermectin
The clothing, bedding, and other items will also need to be treated. They should be washed with soap and hot water and dried in a hot dryer.
The items which cannot be washed, should be sealed in a plastic bag for two weeks. The combs and brushes should be soaked in hot soapy water for at least 10 minutes.
8. Mole
Moles can present as brown, black, blue, pink, or skin-colored spots on the skin. They can be a flat lesion called a macule, or they can be raised forming a papule or nodule. One may have one mole or multiple moles anywhere on the body.
Cause
These occur due to the proliferation of melanocytes, the cells that give pigment to our cells. They may be present at birth or may appear later in life.
Treatment
Most of the moles are harmless and don’t require treatment. If needed, they can be removed in a doctor’s office.
In addition, you should always check your moles for any unusual changes like different shades of color, irregular borders, asymmetry, increase in size > 6mm, and any bleeding or itching. These may be signs of a type of skin cancer called melanoma.
9. Ringworm
Red circular bumps on the scalp can occur due to ringworm. Ringworm of the scalp, also called tinea capitis, is a contagious fungal infection that involves the scalp and hair. The fungus invades the hair making it brittle and prone to breakage. It is commonly seen in children.
It is of types:
- Noninflammatory types can present with a gray patch, scaly areas, or patches with hair breakage which may appear as black dots.
- Inflammatory types can present with red patches, pus-filled bumps, yellow crusting, and areas of hair loss.
Cause
Ringworm is caused by a group of fungi called dermatophytes. It can spread by direct contact with ringworm lesions, infected animals, contaminated surfaces, or soil.
Treatment
Ringworm of the scalp does not respond to over-the-counter antifungal topicals as it does not penetrate the hair. One will need prescription oral antifungal medications like Griseofulvin and terbinafine to completely cure it.
Your doctor may recommend the use of anti-dandruff shampoo to prevent the spread of the fungus. If treated early, complications like permanent hair loss can be prevented.
You can find more articles on ringworm here.
10. Epidermoid cyst
Epidermoid cysts can present as skin-colored or white bumps on the scalp. These are lined by squamous epithelium and are filled with keratin. They are usually asymptomatic, but if they get inflamed, they can become painful. In some cases, the cyst wall can rupture.
Sometimes, these are referred to as sebaceous cysts, but they are entirely different and far less common than epidermoid cysts.
Cause
These occur due to injury or blocking of the hair follicle. They may be related to some genetic conditions like Gardner syndrome.
Treatment
They usually do not require treatment. If the cyst becomes inflamed, intralesional steroids may be helpful and if there is any infection, antibiotics may be prescribed.
To get rid of it, the entire cyst wall needs to be excised surgically.
11. Pilar cyst
Pilar cysts, also known as trichilemmal cysts, commonly form lumps under the skin on the scalp. They may appear as smooth, skin-colored bumps. If inflamed, these cysts can change to a pink or red color and may become painful.
These are filled with keratin. The cyst wall is thick and usually does not rupture, unlike the epidermoid cyst.
When it is examined under a microscope, the lining epithelium of the cyst lacks a granular cell layer which helps in differentiating it from the epidermoid cyst.
Cause
A pilar cyst arises from the outer sheath of the hair follicle. The development of these cysts may be related to genetics.
Treatment
They are usually harmless and if they are not causing any symptoms, they might not need removal.
If required, they can be removed surgically.
12. Shingles
Shingles are a viral infection that can lead to fluid-filled bumps on the scalp on one side (left or right).
The appearance of bumps is usually preceded by itching or a burning sensation. The blisters eventually crust and scab. One may have other systemic symptoms like fever or fatigue.
Cause
It occurs due to a type of herpes virus, called Varicella-zoster virus. This virus causes chickenpox and once the person is infected, it stays in the body.
Years later, it may reactivate due to stress, underlying medical conditions like diabetes or cancer, some medications, or a weakened immune system, leading to shingles.
Treatment
Your doctor may prescribe antiviral medications which can help in faster healing of the skin lesions and can also prevent complications. Medications to reduce pain may also be prescribed.
13. Lipoma
Lipomas are benign lumps, consisting of fat cells, that form under the skin. They commonly appear on the neck, shoulders, trunk, and limbs; however, these lumps can appear anywhere on the body, including the scalp.
Lipomas have smooth surfaces and feel rubbery. They move freely when pressed with a finger. They are usually asymptomatic unless they are near nerves or contain blood vessels, in which case, they can be painful.
Cause
The exact cause is not clear; however, genetics may play a role in it.
Treatment
The fatty lump can be removed by a needle called liposuction or it can be excised surgically.
14. Cherry angiomas
Cherry angiomas, also referred to as red moles, are benign skin growths that may appear as red bumps on the scalp. Their size usually varies between a pinprick and 5 mm.
Cherry angiomas are not itchy or painful and one may not even notice them on the scalp.
These are commonly seen in adults over the age of 30, and their prevalence increases as one gets older.
Cause
These red moles are composed of a cluster of capillaries which are small blood. The exact cause behind their formation is not known.
However, several factors are linked to their occurrence, including age, genetic predispositions, hormonal fluctuations such as those experienced during pregnancy, exposure to certain medications or chemicals, a weakened immune system, and conditions like diabetes.
Treatment
Cherry angiomas are harmless and do not require treatment. However, if they trigger symptoms or for cosmetic reasons, they can be removed in a doctor’s office using procedures like laser therapy, cryotherapy, electrodesiccation, or even surgical removal.
Read more about cherry angiomas on the scalp here.
15. Actinic keratosis
Rough bumps on the scalp can sometimes be due to actinic keratosis. Actinic keratosis is a precancerous lesion that if left untreated can progress to squamous cell carcinoma in 5-10% of cases.
It is usually seen on sun-exposed areas like the scalp, face, and neck. It can present as a red, pink, tan, or brown skin lesion with a rough or crusty surface.
Cause
It occurs due to DNA damage in the epidermal cells which form the top layer of our skin.
Treatment
It can be treated with:
- Topicals like 5- fluorouracil, imiquimod, ingenol mebutate, or diclofenac.
- Laser.
- Freezing.
- Local excision.
16. Skin cancer
A scalp bump can rarely be due to skin cancer. Scalp is exposed to the sun which can lead to DNA damage and cancerous growth.
The three main types of skin cancer are:
- Basal cell carcinoma is the most common type of skin cancer. It can present as a shiny bump, scaly patch, pigmented lesion, or scar-like area.
- Squamous cell carcinoma may present as a firm nodule, wart-like growth, non-healing ulcer, or scaly spot.
- Melanoma is a cancer of melanocytes and may present as an unusual pigmented lesion with an irregular border.
Treatment
The treatment varies and depends on the type and staging of cancer. The treatment may include surgical excision of the tumor, removal of lymph nodes, chemotherapy, or other treatments.
To prevent skin cancer, always protect your scalp by wearing hats and applying broad-spectrum sunscreen.
Key points
Bumps on the scalp can result from various rashes, infections, or skin growth. The appearance and accompanying symptoms may help in identifying the cause.
For instance, red bumps on the scalp could be a sign of conditions such as psoriasis, ringworm, contact dermatitis, atopic dermatitis, head lice, acne, folliculitis, shingles, or cherry angiomas. Similarly, scalp cysts or pus-filled folliculitis spots may present as white bumps on the scalp.
Itchy bumps on the scalp could result from conditions like hives, psoriasis, contact dermatitis, atopic dermatitis, shingles, ringworm, or head lice.
Pimple-like bumps on the scalp that cause pain are usually due to folliculitis, while other causes of painful scalp bumps include an inflamed cyst, inflammatory acne, or shingles.
Some of these bumps can be treated at home, while others may require medical intervention, such as topicals, oral medication, or a procedure.
Any scalp bump that doesn’t go away, grows rapidly, causes extreme pain, or looks unusual should be examined by a doctor. Early diagnosis and treatment can prevent complications.
References
- Head lice. American Academy of Dermatology Association.
- Winters RD, Mitchell M. Folliculitis. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- Scalp eczema. National eczema Society.
- Al Aboud AM, Crane JS. Tinea Capitis. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan.
- Kapadia A. 2014. Trichilemmal cyst. DermNet.
Disclaimer: This blog post is for information purposes only and does not replace medical advice.