Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 23, 2016

Cellulitis is an infection involving the area of tissue just below the skin. Although commonly found on the face, arms, and lower legs, cellulitis can affect any part of the body. If not treated properly, this condition can lead to blood infection or bone infection, inflammation of the lymph nodes, or possibly gangrene. In severe cases, death may occur.


Definition & Facts

A bacterial infection, cellulitis specifically affects the dermis which is the layer of skin below the epidermis and above subcutaneous fats, most often in body extremities. The most common place for the condition to occur is the lower leg. In a reported 95% of cases, patients have reported improvements within seven to ten days of treatment.

In 2013, cellulitis was reported in 37 million people. Although a treatable condition, cellulitis can lead to death if not treated properly or quickly. Around 30,000 people worldwide were reported to have died from cellulitis complications in 2013. The condition is estimated to be the cause of up to 14% of emergency room visits, and around 7% of hospital admissions each year. 

Symptoms & Complaints

In its earliest stages, cellulitis presents as a small area of tenderness, with swelling, warmth, and redness of the skin. As the condition progresses, the patient may develop a fever and note a pus-filled abscess in the central area of the wound.

If cellulitis persists, the patient will often go on to develop shaking, chills, an overall feeling of illness, fatigue, dizziness, a feeling of being light headed, muscle aches, and sweating. Signs that cellulitis is spreading and needs immediate, urgent care include: 

  • Drowsiness: Usually found in patients who are sixty or older, drowsiness with this condition can be an indication of serious infection. This occurs more frequently in female patients than male patients. Medical help should be sought immediately.
  • Lethargy: Lethargy is a lack of energy and enthusiasm. Patients with a severe case of cellulitis may experience lethargy as the infection spreads.
  • Blistering: Cellulitis blisters will present as large boil-like areas around the rash, and usually signify the onset of skin necrosis
  • Red streaks from the site of infection


Most cases of cellulitis are caused by bacteria entering the wound tract, usually Staphylococcus or Streptococcus bacteria. The most common sites of the infection include surgical incisions, insect bites, and cuts. While anyone can get cellulitis, certain individuals are more at risk. These individuals include those with:

  • Diabetes: Due to poor blood circulation in the lower extremities, diabetics are at an increased risk of developing cellulitis. This impaired circulation can lead to ulcers in the feet and lower legs of a patient. Poor control of glucose levels contributes to the development of bacteria that cause cellulitis, and facilitates rapid growth of the bacteria if the infection enters the bloodstream. Because diabetes can cause neural degeneration, infected diabetic ulcers may not be painful for the patient thus delaying diagnosis and treatment.
  • Weakened immune systems: Taking immunosuppresive drugs increases the likelihood of a cellulitis infection. Also at risk are patients with illnesses such as chickenpox and shingles, as these cause blisters that break open and provide a gap through which the bacteria can enter. 
  • Dense populations: Those who share hygiene facilities and common living quarters are also at a higher risk of developing cellulitis due to how bacteria spreads more quickly among those in close contact. These populations include those living in military barracks, dormitories, oil rigs, nursing homes, and homeless shelters.

Diagnosis & Tests

To diagnose cellulitis, a doctor will examine the affected area for redness, swelling, and may mark the area of the rash to track its growth. To check for infection, doctors may also examine the lymph nodes and test any fluids that have accumulated at the affected site. Blood tests to rule out a blood clot, which has similar symptoms to cellulitis, may also be ordered, and many doctors will also order a complete blood count, or CBC, to test for infections as well.

Treatment & Therapy

A patient diagnosed with cellulitis will be given a 10-to-14 day course of oral antibiotics. Although symptoms may clear up within three days of starting the antibiotics, patients must continue to take the medication or risk a relapse. Cellulitis patients suffering from intense pain may also be prescribed a pain medication or recommended to seek over-the-counter pain relief. Individuals with weakened immune systems or other chronic health problems may find that oral antibiotics are not effective, and will need to be admitted to the hospital to receive IV antibiotics.

Prevention & Prophylaxis

Preventing cellulitis can be as simple as proper wound care. Clean any breaks in the skin and apply ointment regularly. Cover the wound with a bandage and change it daily until a scab has formed. When changing bandages, watch for signs of infection. These signs will include redness, drainage, and pain. Those with a higher risk for developing the condition should take extra precautions. Steps to take for those at high risk include:

  • Moisturizing: Properly moisturizing skin can help prevent cracking and peeling which made lead to cellulitis.
  • Prompt treatment of superficial wounds: Even minor skin infections can spread from person to person upon contact. Treatment should begin as soon as possible to prevent spread and infection. 
  • Protective gear during work or sports: Athletes and those with physically demanding jobs such as construction workers are at a higher risk of developing the types of wounds that can lead to cellulitis. Wearing gloves, proper footwear, and other protective gear will help prevent injuries which may lead to the condition.