Cellulitis is a common bacterial skin infection. It can occur when bacteria enter your body because of a cut, scrape, or break in the skin, such as a bug bite.

Cellulitis affects all three layers of your skin. It can cause symptoms such as:

  • redness
  • swelling
  • inflammation

Cellulitis is treated with antibiotics. If left untreated, it can become serious, even deadly.

Cellulitis can occur anywhere that a break, cut, or crack in the skin occurs. This includes your face, arms, and eyelids. However, cellulitis most commonly occurs on the skin of the lower leg.

Bug bites, such as those from mosquitoes, bees, and ants, can all break the skin. Bacteria that live on the surface of your skin can then enter those small puncture points and develop into an infection. Aggressive scratching of the bite spots can also open up the skin.

Any bacteria you encounter can find their way into your skin and possibly develop into an infection. You may also introduce bacteria to your skin by scratching with dirty fingernails or hands.

Several types of bacteria can cause cellulitis. The most common are group A Streptococcus, which causes strep throat,and Staphylococcus, commonly referred to as staph. Methicillin-resistant Staphylococcus aureus, or MRSA, can also cause cellulitis.

The symptoms of cellulitis caused by a bug bite include:

  • pain and tenderness that radiates from the bug bite
  • inflammation
  • redness
  • swelling
  • red streaks or spots near the area of the bite
  • skin that feels warm to the touch
  • skin dimpling

If cellulitis isn’t treated, it can develop into a serious infection. Signs of a worsening infection include:

Bug bites aren’t always serious but cellulitis should be taken seriously if it happens. Your doctor can prescribe a round of antibiotics that should eliminate the infection in 5 to 14 days. Catching the infection early is the key to preventing it from progressing.

If the bacterial infection is left untreated, it can spread to your lymph nodes and eventually get into your bloodstream, possibly even your tissues and bones. This is a condition called a systemic bacterial infection. It’s also known as sepsis.

Sepsis is life-threatening and needs immediate medical attention. The infection can spread to your blood, heart, or nervous system. In some cases, cellulitis can lead to amputation. Rarely, it can cause death.

Advanced cellulitis might require hospitalization so your doctor can monitor you for worsening symptoms. They’ll also administer intravenous (IV) antibiotics.

Cellulitis isn’t always an emergency but it does need treatment. If the area of red, inflamed skin does appear to be expanding but you have no other signs of a worsening infection, you can call your doctor and request an office appointment.

However, if the tender, swollen spot is growing or you show signs of a worsening infection, such as a fever or chills, you should seek emergency medical attention. Your infection may become serious if it’s not treated quickly.

One way to monitor the inflamed area for growth is to gently draw a circle around the swollen area of skin. A felt-tip marker may be more comfortable than a ball-point ink pen. Then, check the circle and skin two to three hours later. If the redness is beyond the circle you drew, the inflammation and infection are growing.

If you wake up after a night on your back porch to find your legs and arms covered in the red welts of mosquito bites, you can take steps to prevent those bug bites from becoming infected.

These techniques may help you prevent cellulitis if you have any cuts, scrapes, or bites on your skin:

  • Don’t scratch. It’s easier said than done, of course, but scratching is one of the primary ways bacteria can enter skin and develop into an infection. Look for anti-itch creams or lotions with mild numbing agents that can help reduce the itching sensation.
  • Wash the bug bite. Clean skin reduces the risk of bacteria finding their way into the bug bite. Use soap and water to clean and rinse the bite and the skin around it. Do this at least once per day until the bite is gone or it develops a scab.
  • Use an ointment. Petroleum jelly or an antibiotic ointment can form a protective barrier over the bug bite. The antibiotic ointment can help reduce swelling and inflammation, which may cut down on irritation and itching.
  • Cover with a bandage. Once you’ve washed the bite and applied some ointment, cover it with a bandage to protect it from dirt and bacteria. This can also reduce your ability to scratch. Change the bandage daily to keep the area clean and cut down on the risk for infection.
  • Apply ice. You can put ice packs wrapped in a towel directly on the bite. The ice will numb skin and possibly help reduce your urge to scratch.
  • Trim your fingernails. A plethora of bacteria, as well as dirt and grime, live under your fingernails. Reduce your risk of spreading the germs under your nails to your skin by cutting your nails shorter and scrubbing them clean with a nail brush, soap, and warm water.
  • Moisturize. With all the additional washing, the skin around the bug bites may become dry. Use a mild moisturizing lotion to help hydrate your skin and prevent cracks. The best time to apply this lotion is soon after a bath or shower.
  • Watch for signs of infection. If the area around the bug bite starts to turn red and swell, you may have developed an infection. Monitor the spot and your symptoms. Seek emergency medical treatment if you develop a fever, chills, or swollen lymph nodes. These signs are more serious and could become dangerous if left untreated.

Cellulitis is a common bacterial infection that can develop from a cut, scrape, or wound, such as a bug bite. When an insect bites or stings you, a tiny hole forms in your skin. Bacteria can enter that opening and develop into an infection. Likewise, scratching or itching a bug bite can tear the skin, which also creates an opening for bacteria.

When an infection develops in your deepest skin layers, you may experience redness, swelling, and inflammation around the bite. Make an appointment to see your doctor if you develop these symptoms.

If you also begin to develop a fever, chills, or swollen lymph nodes, you may need to seek emergency treatment. These are symptoms of a worsening infection, and they should be taken seriously.

Cellulitis can be treated if it’s caught early and doesn’t progress. That’s why it’s important to get your doctor’s help sooner rather than later. The longer you wait, the greater your risk for complications.