What is cellulitis?

Cellulitis is a painful bacterial skin infection that causes the affected area to appear red and swollen as well feel tender and warm to the touch.

Although cellulitis can appear anywhere on the body, it most frequently affects your lower legs. It typically affects the surface of the skin, but it can spread to your lymph nodes, bloodstream and underlying tissues.

Causes of cellulitis

Cellulitis occurs when bacteria enters the skin through a crack or break in the skin such as where you have a cut, ulcer, athlete’s foot or had recent surgery. It is typically caused by streptococcus and staphylococcus, bacteria that normally lives harmlessly on the surface of intact skin. If the skin is broken by a minor cut, abrasion, bug bite or other injury, the bacteria can cause an infection on the top layer or deeper layers of the skin.

There has been an increase in the prevalence of methicillin-resistant staphylococcus aureus (MRSA) in recent years. This type of cellulitis is harder to treat.

Risk factors for cellulitis

There are a variety of factors that increase your likelihood of developing cellulitis including:

  • Weakened immune system
    Children, the elderly and people who have medical conditions such as HIV, cancer or diabetes or have weaker immune systems are more likely to develop cellulitis.
  • Being overweight or obese
    If you are overweight or obese, it is harder for you to fight infection such as cellulitis from developing.
  • Lymphedema
    If you have lymphedema, a condition where fluid builds up in the arms or legs, you are more likely to develop cellulitis.
  • History of skin problems
    People who have a history of skin problems, frequent skin injuries or have a skin condition that causes a cut in the skin such as shingles or athlete’s foot are more likely to develop another infection.
  • Injection drug use
    Skin infections such as cellulitis are more common in people who are injection drug users.

Symptoms of cellulitis

Symptoms of cellulitis generally occur on one side of the body. Symptoms include:

  • Red spots on the skin that continue to expand
  • Swelling
  • Pain and/or tenderness in the affected area
  • Fever
  • Warmth
  • Blisters
  • Dimpling in the skin
  • Shaking
  • Chills
  • Fatigue
  • Abscess with pus formation
  • Lightheadedness
  • Muscle aches

Diagnosis of cellulitis

Your doctor is typically able to diagnose cellulitis during a physical exam. Your doctor will look for red, swollen skin and glands and warmth in the affected area. If the infection looks severe, your doctor will likely do a blood draw or order a tissue culture to test for the presence of bacteria.

Treatments for cellulitis

Cellulitis can be treated with antibiotics. The duration of the treatment can last from 10 to 21 days depending on the severity of your infection. Although your symptoms will begin to improve after a few days of starting the antibiotic, you should continue to take all the medication as prescribed.

If your symptoms intensify, or you develop a fever, call you doctor right away. You may need to be hospitalized and be given IV antibiotics if you have any of the following symptoms:

  • High fever
  • High blood pressure
  • Compromised immune system because you are very young, elderly or have other medical conditions
  • Blood infection

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