Raised skin bumps can result from a number of conditions, benign or harmful, but in most cases they are harmless. An infection, an allergic reaction, a hereditary condition, or even skin cancer can cause bumps to form on your skin.
Skin bumps can vary in appearance depending on the cause. They may be skin-colored or discolored. They may be itchy or not itchy, large or small, multiple or single. Some are hard while others feel soft and movable. Most bumps need no treatment unless they cause you discomfort. If you are concerned about any changes in the condition of your skin, you should see your doctor.
There are many different conditions that can cause raised bumps to appear on your skin. The most common causes of bumps are harmless and do not require medical treatment unless you have discomfort:
- Cysts are growths that develop under the skin. They feel like a small ball and can be moved around slightly.
- Angiomas are blood vessels that collect together and create a raised, reddish spot on or bump under the skin.
- Seborrheic keratosis are round spots on the skin that appear most often in middle age. They may be skin-colored, brown, or black.
- Moles are flat or raised bumps on the skin that are usually benign and range from skin-colored to dark brown.
- Acne causes skin bumps that can range from very small to bigger and painful. The bumps are usually accompanied by redness and swelling.
- Lipomas are collections of fatty tissue under the skin and are often painless.
- Corns or calluses, usually on the feet, are rough, thickened areas of skin.
- Allergic eczema is an allergic skin reaction that produces redness, itching, and irritation.
- Psoriasis is a skin disease that produces scaly, red, inflamed patches on your skin that may be itchy.
- Keloids are smooth, raised growths that form around wounds.
- Keratosis pilaris is a skin condition characterized by overgrowth of a protein called keratin. It causes small bumps around hair follicles on the body.
- Skin tags are small, fleshy flaps of skin. They usually grow on the neck or armpits.
- Mollusca are bumps in the groin area that are usually small and flesh colored. They arise from sexually transmitted diseases, but usually disappear after a couple of years.
- Warts, which are caused by a virus, are raised, rough bumps, usually on the hands and feet.
- Cold sores are bumps around the mouth that are caused by the herpes virus.
- Boils are infected hair follicles that are not life-threatening, but often require treatment to heal.
- Insect stings and bites are often itchy and swollen. They may cause pain that lingers.
Less commonly, raised skin bumps are caused by conditions that require treatment. Certain bacterial and viral infections cause bumps and will only worsen without a diagnosis and treatment:
- Staphylococcus aureus (MRSA)
- scarlet fever
- genital herpes
- genital warts
Another type of skin bump to be concerned about is that caused by skin cancer. There are several types of skin cancer, all requiring treatment:
- Basal cell carcinoma appears on sun-exposed skin and produces pain and bleeding in the early stages. The associated bumps may be discolored, shiny, or scar-like.
- Actinic keratosis is a precancerous formation that appears as a scaly or crusty bump on the skin. You will be more likely to feel it than to see it.
- Squamous cell carcinoma is a type of skin cancer that often starts as actinic keratosis. It may be crusty, pink in color, and raised above the skin.
- Melanoma is the most serious type of skin cancer and begins as an atypical mole. Cancerous moles are often asymmetric, multi-colored, large, and has irregular borders.
Skin bumps that are harmless and need no treatment can be removed for cosmetic reasons. For instance, your dermatologist can freeze skin tags or warts to remove them. You can have cysts or lipomas removed surgically. Other bumps that are itchy or irritated may be treated with topical ointments.
If your skin bumps are caused by an infection, your doctor will recommend a treatment plan. For a bacterial infection, like MRSA or syphilis, you may need a course of antibiotics. Some viral infections cannot be cured, like herpes. However, your doctor can give you medications to treat the symptoms.
For any bumps in which cancer is a possibility, your doctor will perform a physical examination, and then remove a sample for a biopsy. The biopsy can show you if the bump is cancerous or precancerous. If it is only precancerous, your doctor will most likely remove it completely and then check the spot from time to time.
For most skin bumps, the long-term outlook is excellent. The majority of bumps are caused by benign, often temporary conditions. In the instance that you have an infection, treatment should either clear it up, or effectively treat the symptoms. If you catch a patch of skin cancer early, your prognosis is good with treatment, but you will require follow-ups to be sure it does not return. The outlook for more advanced forms of cancer varies with each individual situation.