Pimples on Scalp: Why They Appear and How to Treat Them

Published on August 26, 2023 .

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Woman looking at her scalp for pimples — Image by triocean via Shutterstock

Pimples, or bumps, on the scalp are a common skin problem. Various health issues can cause pimples on the scalp. Most are harmless and resolve on their own. However, some are malignant or require urgent medical attention. Read on to learn what causes pimples on the scalp and how to treat and prevent them.

Various conditions, such as acne, folliculitis, pilar cysts, seborrheic dermatitis, psoriasis, seborrheic keratosis, skin cancer, or lipoma, can cause pimples (bumps) on the scalp.
Treatment of pimples on the scalp is specific to the underlying condition, and there is not just one general treatment for all problems.
If your condition does not improve or worsens, see your doctor immediately for prompt treatment.

What are pimples on the scalp?

Pimples (bumps) on the scalp can present with lesions. They may look like pink bumps with a smooth top, crusting, pus heads, blisters, or bumps under the skin. It is also possible they could be solitary lesions or appear in clusters. Many are asymptomatic, while others are itchy, sore, tender, or painful. Since they appear on the scalp, the pimples may also cause temporary hair loss, which may progress to permanent hair loss if left untreated.

Causes of pimples on the scalp

A wide variety of skin conditions can cause pimples on the scalp. These range from infectious to inflammatory to cancerous. Proper diagnosis is critical to correct and effective treatment.

Acne

Acne is an inflammatory condition characterized by pores clogged with dirt, oil, dead skin cells, and bacteria. Genetics, stress, hormones, some medications, certain medical conditions, a diet rich in carbs and sugars, and comedogenic products can cause acne. Patients present with blackheads, whiteheads, small pink bumps (papules), larger tender pink bumps (nodules), and large painful bumps under the skin (cysts).

Folliculitis

Folliculitis is an infection of the hair follicles, usually with bacteria but sometimes fungus or yeast. Patients report pink bumps, some with pus heads that may be itchy or tender. They form around the hair follicles. It usually occurs from friction, wearing tight hats, headgear, or headbands, or not bathing immediately after sweating.

Pilar cyst

A pilar cyst occurs when a clogged pore creates a sack under the skin containing keratin and skin debris. The exact cause is unknown. They usually present as skin-colored bumps under the skin that could become inflamed or infected. Pilar cysts are mostly asymptomatic unless they become infected, then they will be red and painful.

Skin cancer

The most common forms of skin cancer are basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma (MM). Cumulative excess sun exposure causes skin cancers however, MM also has a genetic component. BCCs are pink pearly bumps with broken blood vessels. SCCs look like crusted pink bumps. MM may appear as irregular, asymmetric, multicolored flat spots or bumps.

Seborrheic dermatitis

Seborrheic dermatitis is an inflammatory condition that may present with scaly pink bumps, possibly with crusting or excoriations. The cause is largely unknown but may be genetic or related to a hypersensitivity reaction to yeast. It can be itchy or sore.

Psoriasis

Psoriasis is an inflammatory condition with autoimmune and genetic components. In some cases, medications, like beta blockers for high blood pressure, may cause psoriasis. Psoriasis causes an excess production of skin cells, which leads to the presentation of pink bumps with crusty or scaly tops. It can be itchy or sore if the lesions get large.

Seborrheic keratosis

Seborrheic keratosis is a lesion that presents with pink, tan, brown, or black bumps that may or may not be crusty. The cause is unknown. These benign lesions may, at times, itch or become sore.

Lipoma

Lipomas are benign localized growths of fat cells under the skin. They appear as asymptomatic, skin-colored bumps under the skin, that may become red and tender if irritated. The exact cause is unknown, but there may be a genetic component.

Treatments for pimples on the scalp

Treatment for pimples on the scalp is specific to the exact cause. This is why the correct diagnosis by a dermatologist is critical. It is also important to institute prompt treatment for the condition before it worsens.

Cause	Over-the-counter treatments	Medical treatments
Acne	Salicylic acid washes, shampoos, or creams; benzoyl peroxide creams; adapalene cream or gel; proper hygiene; a diet low in dairy and carbs; lower stress; and stop smoking.	Topical or oral antibiotics, topical or oral retinoids, and light or laser therapy.
Folliculitis	Warm compresses, good hygiene, wash with antibacterial soap, and antibacterial ointments.	Topical or oral antibiotics.
Pilar cyst	N/A	Incision and drainage, surgical excision, and injection with steroids (small lesions).
Skin cancer	N/A	Surgical excision, radiation, topical or injection of chemotherapy, electrodesiccation and curettage, cryotherapy (small lesions), and oral or intravenous chemotherapy.
Seborrheic dermatitis	Medicated shampoos (salicylic acid, tar, zinc pyrithione, and selenium sulfide) and hydrocortisone cream.	Topical, oral, or injected steroids; steroid shampoos; light therapy; topical immunomodulators; and systemic immunosuppressants or immunomodulators (severe cases).
Psoriasis	Medicated shampoos with tar and hydrocortisone cream.	Topical, oral, or injected steroids; steroid shampoos; topical immunomodulators; light therapy; and systemic immunosuppressants or immunomodulators (severe cases).
Seborrheic keratosis	N/A	Liquid nitrogen, surgical excision, curettage, electrocautery, and topical retinoids, urea, acids or peroxide.
Lipoma	N/A	Surgical excision, liposuction, or steroids injection (small lesions).

How to prevent scalp pimples

Some of the causes of pimples on the scalp are preventable. Since the cause of seborrheic keratosis, pilar cysts, and lipomas are unknown, they are not preventable. You also cannot prevent seborrheic dermatitis or psoriasis from developing since they have a genetic component; however, you may be able to prevent outbreaks with treatment.

Here are some prevention tips:

Acne. Practice good hygiene by washing and moisturizing twice daily and after sweating. Exfoliate once or twice a week. Avoid excessive carbs and sugars, smoking, and stress. Use only non-comedogenic products. Treat medical conditions or change medications that may cause acne.
Folliculitis. Like with acne, practice good hygiene by washing and moisturizing twice daily and after sweating. Exfoliate once or twice a week. Avoid friction, tight-fitting hats, headbands, or headgear.
Skin cancer. Practice good sun protection and avoid peak hours of sun exposure (10 a.m.–4 p.m.). Good sun protection includes daily use of a broad spectrum sunscreen with SPF 50, reapplying sunscreen every 1–2 hours you are in the sun, and wearing a wide-brimmed hat, sunglasses, and UPF clothing.

When to see a doctor for pimples on the scalp

If your condition is not improving, worsening, or spreading, see your dermatologist immediately. If the pimples become red, warm, tender, swollen, or ooze pus, these are possible signs of infection, and prompt medical treatment is necessary. If you have a fever, chills, nausea, or vomiting associated with your scalp pimples, go to the emergency room. The quicker you receive treatment, the faster you will recover and the less likely you are to experience a possible life-threatening situation.

Many different skin problems, covering the spectrum from infection to inflammation to malignancy, can cause scalp pimples or bumps. The exact cause of the scalp pimples will dictate treatment and prevention. If you are unsure of the cause of your scalp pimples or your over-the-counter treatments have not cured your problem, you must see your dermatologist immediately. Prompt treatment will give you a quicker resolution of your problem and prevent serious consequences.