Cellulitis is caused by a bacterial infection that enters the skin through another wound.

Cellulitis is a bacterial infection of the dermal layer of skin and may extend to the subcutaneous tissue. The word cellulitis translates to “inflammation of the cells.”

It is typically caused by the bacteria Streptococcus pyogenes or Staphylococcus aureus, which are part of the normal flora of the skin, but do not cause infection while on the skin’s outer surface. For the bacteria to get in they need a route – a break in the skin caused by an ulcer, cut, abrasion or bite. The moment the bacteria pass the surface of the skin, the warm, moist nutrient rich environment allows infection to spread quickly.

Symptoms of Cellulitis

Although symptoms may appear in any part of the body, the legs are most commonly affected. The body’s response is inflammation, indicated by pain, redness, heat and swelling. The infected area may also display a red patch that grows rapidly within the initial 24-hour period. A heavy red line that points in the direction of the heart could appear, suggesting an infection within the lymph vessels (lymphangitis). If the cellulitis is in the leg, the lymph glands in the groin may be tender. Additional symptoms may include influenza-like symptoms with a fever, chills, tiredness, sore muscles and an overall feeling of malaise or body-ache. Some people also report nausea, vomiting, stiff joints, and hair loss around the infection.

Risk Factors

The elderly and obese are especially vulnerable to contracting cellulitis. Diabetics are more susceptible to cellulitis than the general population because of impairment of the immune system; they are especially prone to cellulitis in the feet, because the disease causes impairment of blood circulation in the legs, leading to diabetic foot ulcers. Poor control of blood glucose levels allows bacteria to grow more rapidly in the affected tissue, and facilitates rapid progression if the infection enters the bloodstream. Those who have suffered poliomyelitis are also prone because of circulatory problems, especially in the legs.

Immunosuppressive drugs, and other illnesses or infections that weaken the immune system are also factors that make infections more likely. Chickenpox and shingles often result in blisters that break open, providing an opening in the skin where bacteria can enter. Lymphedema, which causes swelling on the arms or legs, can also cause risk. A person who has had cellulitis is at greater risk for a recurrent outbreak. Even though cellulitis is not contagious, there is a higher incidence of this infection among people who share common living quarters such as long term care. Predisposing conditions for cellulitis include insect or animal bites, blistering, tattoos, rashes, recent surgery, athlete’s foot and injecting drugs.

How is Cellulitis Diagnosed?

The resident’s history, contributing factors and symptoms help confirm cellulitis. The appearance of the skin will assist the physician in determining a diagnosis. High-risk residents with systemic signs may need blood and urine testing to rule out systemic infection.

Note: Other conditions may have caused the symptoms such as Lyme disease, varicose eczema, bone infection and necrotizing fasciitis so be certain to report the condition to the physician.

Treatment of Cellulitis


  • Oral antibiotics, more severe cases may require IV antibiotics; steroids may also be indicated
  • Pain management
  • Manage the disease that contributed to cellulitis (diabetes, circulatory deficits)

Clinical Management

  • Elevate affected area above heart level to reduce swelling and pain
  • Encourage fluids
  • Debridement

Complications of Cellulitis

  • MRSA
  • Abscess
  • Septicemia
  • Permanent swelling
  • Necrotizing fasciitis
  • Death