How do moles become infected?

A mole is a colored spot on your skin caused by a high concentration of pigment-producing cells called melanocytes. The medical term for a pigmented mole is a melanocytic nevus, or simply nevus. Multiple moles are called nevi.

Most moles are benign. When a mole is present from birth, it’s often called a birthmark.

A mole can become infected from scratching or some other irritation. An infection can also be caused by the presence of a foreign organism, such as a fungus, or virus. More commonly, it’s caused by bacteria that normally live on your skin.

If you see bleeding or a change in the appearance of a mole, it’s important to see your doctor. Don’t just assume the mole is irritated and try to manage it yourself. It could be a sign of a developing skin cancer.

It’s not known what causes a mole to appear. But most people have at least one mole and often many more.

A mole can become infected just like any other part of your body.

Symptoms of an infected mole include:

  • redness or swelling
  • bleeding
  • discharge of pus
  • pain or fever

Most commonly, a mole becomes infected due to bacteria. However, a skin virus or fungus could also be a cause. Bacterial infections of the skin can be contained within the mole or be widespread. A widespread bacterial infection of the skin is known as cellulitis. Cellulitis is most commonly caused by staphylococcus (staph) or streptococcus (strep) bacteria, which are generally present on the skin in low levels. During an infection, these bacteria grow to abnormally high numbers.

Some of the reasons that a mole might become infected include the following:

Scratching or picking

Scratching or picking at your mole can create openings in the skin that allow bacteria to enter and gain a foothold. The bacteria, virus, or fungus may also be present under your fingernail.

Abrasion or wound to the mole

A scrape or cut might occur at the site of a mole. This can open up your skin to bacterial, viral, or fungal infection. If you have a mole in a place that is frequently rubbed or bumped, you might consider asking your doctor to remove it. Moles located along bra lines, around the waist, under the arm, or in the groin are easily irritated.

Ingrown hair

Moles can involve a hair follicle. It’s common to have a hair coming out of a mole, and this isn’t a sign of a serious medical condition. But, if the hair gets ingrown it may create a small wound that could allow bacteria to enter.

In general, anything that could damage the skin in or around the mole could lead to an infection.

If you suspect your mole may be infected and it hasn’t improved within two days, it’s always a good idea to see a doctor. They can determine the right course of treatment after making a diagnosis. A doctor will be able to tell if the mole is showing signs of a developing skin cancer. Moles that bleed regularly or don’t heal properly may be cancerous.


If you suspect a minor infection, your first step is to gently clean the area several times a day with soap and water and pat it dry with a clean towel. Over-the-counter antibiotic ointments such as a triple antibiotic (Neosporin, Bacitracin) are typically not recommended.

Ongoing research suggests that these topical medications may not be beneficial. They can cause allergic reactions and cause bacteria to become resistant to antibiotic treatments, leading to more serious infections.

Once the mole is clean and dry, depending on the location, you may need to keep the area covered to avoid irritation. Avoid any further picking or squeezing of the area.

By keeping it clean, the infection should begin clearing up in a day or two. However, if this is not the case or you have diabetes, conditions that affect your immune system, or a history of serious skin infections, see your doctor right away.

Also, if the area is painful, swollen, bleeding, or getting bigger, or if you have a fever, see a doctor. You may need a prescription for an antibiotic by mouth to get rid of the infection. Serious skin infections can require a hospital stay for antibiotics by vein (IV).

In the event that the mole shows signs of skin cancer, your doctor can take a small sample of the mole (biopsy) or remove the mole completely. They also may refer you to a specialist for further examination and treatment.


If your mole is in an area where it tends to get irritated by rubbing or catching on clothing and other objects, you can consider asking your doctor to remove it.

Mole removal should only be performed by a qualified doctor. This may be your primary care doctor, a dermatologist, or a surgeon. Trying over-the-counter mole removal ointments and preparations or home remedies is not recommended and can be dangerous. They may produce an infection where there wasn’t one before. They can leave a thick, unsightly scar in place of the mole. More importantly, they can lead to the improper treatment of skin cancer, causing serious complications.

Removal in a doctor’s office involves numbing the area with local numbing medication, and then removing the whole mole with sterile surgical instruments. Smaller and shallower moles may not even require stitches.

Keep it clean

If you have any break in your skin near a mole, gently clean it immediately with soap and water several times a day. Cover the wound with a clean, dry dressing if it will be exposed to dirt or contaminants.

Don’t pick or scratch

Avoid the temptation to pick at or scratch your moles.

Consider removal

If your mole is in an area where it’s frequently irritated by rubbing or catching on things, discuss removing it with your doctor.

Almost everybody has one or more moles. Infected moles are not common, but they do happen. If home cleansing doesn’t cure it quickly, you should see a doctor. Because any changes in a mole can be a sign of a developing skin cancer, it’s important to see your doctor if you’re having a problem with a mole.