What can cause raised skin bumps?

Acne is one of the most common types of skin condition, affecting up to 50 million Americans each year.

The way the skin responds to acne varies, but it can cause raised bumps on the skin, commonly called “blemishes,” “pimples,” or “zits.” These commonly appear on the face, chest, or back.

Acne in the form of blackheads or whiteheads causes smaller bumps, while papules and pustules are slightly larger.

Treatment

There are three categories of acne severity — mild, moderate, and severe.

Mild acne has the lowest number of lesions and is treatable with topical medication or laser and light therapy.

Moderate acne is more invasive and may require antibiotics or antiandrogens for treatment.

Severe acne has the greatest number of most inflamed lesions.

Treating severe acne may require oral isotretinoin, such as Accutane, which is a strong course of treatment.

The American Academy of Dermatology (AAD) notes that darker skin may particularly benefit from using a combination of retinoid and benzoyl peroxide.

Learn more about treating acne on black skin here.

Home treatment options for acne includeTrusted Source the external use of:

• aloe vera
• tea tree oil
• propolis, which is found in bee products
• benzoyl peroxide
• salicylic acid
• glycolic acid.

Learn more about prevention and management tips for acne here.

The body produces an allergic reaction when the immune system has an extremeTrusted Source response to an otherwise harmless factor in the environment.

Among other symptoms, raised bumps can appear as a reaction to the triggering allergen.

Skin responses typically appear in areas that have been in contact with the allergens, but they can develop anywhere on the body.

Skin reactions can last for minutes or hours and can appear as hives, contact dermatitis, or other lesions.

Hives

Hives, or urticaria, present as bumps or welts on the skin. On white skin, they appear red. On darker skin, they can be similar to the color of the skin tone. They can sometimes appear lighter or darker than the surrounding skin.

Hives can be acute or chronic. Acute hives typically occur due to exposure to an allergen and should not last for longer than 6 weeks.

Learn more about hives on black skin here.

Contact dermatitis

Contact dermatitis appears when the skin comes into contact with an allergen or an irritant.

A person may notice:

• a rash
• blisters
• itching
• burning
• dry and cracked skin

According to the United Kingdom’s National Health Service (NHS), the rash can appear red on lighter skin and dark brown, gray, or purple on darker skin.

Treatment

Topical antihistamines, corticosteroid creams, and oral corticosteroids are medical options if symptoms develop.

People may also find it beneficial to have a bath and moisturize immediately afterward using emollients.

Blisters are bubbles containing bodily fluids, such as serum, that develop from heat, friction, or chemical exposure, among other causes. The bubbles are present between the upper layers of skin. This creates visible bumps.

Blisters can also contain blood, otherwise known as blood blisters. These can appear red or black.

On dark skin, they will appear lighter than the surrounding skin.

Blisters can be painful, but are usually harmless. They often develop on the feet from wearing shoes, the fingers after using a pen, or other areas of the skin after sun exposure.

Treatment

A person can cover the blister loosely with a bandage.

For those that appear on the bottom of the foot, a person can cut padding into a donut shape, with a hole in the center.

Place this around the blister and cover with a bandage.

Blisters can be inconvenient, but they are the body’s way of protecting the area under the skin. Because of this, it is best to leave a blister intact if one develops.

However, if the blister is causing inconvenience or pain, the AAD states that a person can use a sterilized needle to puncture the outer layer and drain out the fluid.

People should then disinfect the puncture wound with soap and water before sealing it with petroleum jelly. Leave the upper layer of skin intact as it will protect the wound underneath.

There are many different infections that can cause raised skin bumps.

These include:

• Impetigo: This is a bacterial infection, typically caused by staph bacteria, that causes sores and pustules on the skin.
• Chickenpox: This is a viral infection that occurs due to the varicella-zoster virus (VZV).
• Cold sores: These are painful lumps or blisters that appear on the face and around the lips due to infection with the herpes simplex virus.
• MRSA infection: This is a serious bacterial skin infection that presents as a swollen, painful, hot bump on the skin.
• Warts: These are small lumps on the skin that occur as a result of human papillomavirus. On dark skin, they may appear paler than the surrounding skin.
• Scabies: This is a parasitic infection that presents as an itchy, pimple-like rash. It may be harder to see on darker skin, but a person should be able to feel the rash, according to the NHS.
• Molluscum contagiosum: This is a harmless poxvirus infection that causes small, firm bumps to appear. The bumps can be skin-colored or have a more pinkish tone.

Treatment

Treatment will depend on the underlying cause. A person can treat some causes with topical creams and ointments. These include:

• warts
• cold sores
• scabies
• impetigo

Some bacterial causes may require antibiotics, such as MRSA infection.

Skin cancer is the most common type of cancer in the United States, according to the Centers for Disease Control and Prevention (CDC)Trusted Source. It can result from too much sun exposure.

Raised skin bumps can be a sign of melanoma or carcinoma, which are types of skin cancers.

Melanoma

Melanoma tumors often begin in a flat shape as freckles or moles. They develop and form slight lumps as the pigmentation cells grow uncontrollably.

Melanoma tumors may be brown, black, blue, tan, red, light gray, or without color. The growths can be sensitive and itchy and, as they develop, the skin may crust over and bleed easily.

Basal cell carcinoma

Basal cell carcinoma, or BCC, forms a shiny, round, slow-growing bump that people sometimes mistake for acne, a skin injury, a sore, or a scar.

The bumps often grow on the head or neck, but they also develop on the arms, legs, hands, and, despite the lack of sun exposure, the genitals.

BCC bumps are usually pink or red. In some cases, they can also be brown, black, yellow, or white. Symptoms that occur with BCC include itchiness, sensitivity, numbness, and tingling.

Cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma, or SCC, may appear as a crusty or scaly bump or lumpy area of skin. Bumps typically develop on areas that have the most sun exposure, such as the face, hands, or legs. They can be painful and sensitive.

Types of cutaneous SCC include:

• verrucous carcinoma, which a wart-like lump that grows on the bottom of the foot
• cutaneous horn, which is a lesion with a cone shape
• keratoacanthoma, which is a tumor that may resolve itself without treatment
• marjolin ulcer, which is an uncommon tumor that grows from scars or ulcers

Treatment

If a person thinks they may have a cancerous skin bump, they should see a doctor.

Treatment for skin cancer can includeTrusted Source a combination of:

• surgery
• chemotherapy, topical or systemic
• radiation therapy
• immunotherapy
• photodynamic therapy
• drug therapy
• chemical peel

There are many causes of a raised skin bump. Other causes include:

• boils, which are hard, painful lumps filled with pus
• corns, which are hard and thickened areas of skin, typically occurring on the feet
• cysts, which are lumps under the skin that are filled with liquid or semisolid substances
• seborrheic keratosis, which are benign skin growths that appear similar to warts
• lipomas, which are soft, fatty lumps under the skin that do not require treatment
• keloids, which are a type of raised scar that initially appear red, pink, or purple
• keratosis pilaris, which is a harmless skin condition that appears as tiny bumps, mostly on the back of the arm or thighs, that may appear similar to acne
• skin tags, which are harmless skin growths that are typically flesh-colored
• cherry angiomas, which are red papules on the skin that appear red on lighter skin, and blue or purple on darker skin
• pseudofolliculitis barbae, which is an ingrown hair that can appear similar to a pimple

Treatment

Treatment will ultimately depend on the cause. Some skin bumps, such as skin tags and keratosis pilaris, do not require medical treatment.

Others may require surgery or excision.

A person should see a doctor or dermatologist to discuss potential treatment options.

See more about skincare

With most types of skin bump, it is not necessary to call a doctor. However, if a person has concerns about a bump, they should seek medical attention.

It is possible to mistake more severe conditions such as skin cancer for mild acne.

Most people will experience raised bumps on the skin at some point. They come in many shapes, sizes, and colors and may cause symptoms, such as itchiness, or no symptoms at all.

Raised bumps are usually harmless. They can be the result of acne, ingrown hairs, or skin tags, among many other causes. However, raised bumps sometimes indicate skin cancer. It is always best to see a doctor if a person has concerns.