What is Cellulitis

Cellulitis is a bacterial infection that usually occurs in an extremity such as an arm or leg. 

Bacteria will enter a skin trauma and then cause the skin to swell, increase in temperature, turn red, and become tender.  If the infection is left untreated it may spread and evolve into a life threatening condition.  

Two of the most common types of bacteria that cause cellulitis are staphylococcus and streptococcus.  Staphylococcus is a genus of bacteria that looks like a bunch of grapes if viewed under a microscope. 

Streptococcus is a genus of bacteria that looks like a twisted chain when viewed under a microscope. Streptococcus and staphylococcus are part of normal skin flora and will not cause infection unless the skin is broken. 

Conditions that predispose cellulitis are

• athlete’s foot
  
• boils
  
• burns
  
• animal bites
  
• surgery
  
• dry skin
  
• insect bites

People with weakened immune systems such as the elderly and diabetics are at a greater risk of contracting cellulitis.  Any illness, infection or drug that weakens the immune system increases vulnerability to contracting cellulitis. 

Other risk factors for cellulitis are illnesses such as

• shingles,
• chickenpox, and
• lymphedema

All of which can induce risk by causing entry portals for bacteria.  
    
Dense populations that share hygiene facilities such as communal showers and common living quarters have a greater incidence of cellulitis.  Military installations and military boot camps provide an environment where cellulitis can flourish.  

Cellulitis can take days to develop or it can take as little as twenty four hours to evolve into a critical infection.  If treated properly, it can take less than a week to be neutralized with antibiotic therapy. However, severe cases can take months to resolve and can result in disability or death if left untreated.
    
Cellulitis is usually a clinical diagnosis based on the signs and symptoms of the disease because local cultures do not always identify the causative organism.  Blood cultures will not provide evidence of cellulitis infection unless the patient has developed sepsis which is the immune response to a severe infection.    
  
In a minor case of cellulitis, antibiotics taken orally are all that is required for treatment.  Oral antibiotics are usually taken for about ten days and the patient may return to visit the doctor after a couple of days to verify that the antibiotics are working properly.         
    
If the infected patient has a high fever or the oral antibiotics do not work, intravenous antibiotics will most likely be administered.  Usually an antistaphylococcal like flucloxacillin will be used.  

In the most severe cases, cellulitis may spread to the bloodstream and cause septicemia, which even under optimal treatment may result in death. In a case where antibiotic therapy is not successful, surgery that removes the infected tissue may be necessary.  

The best way to prevent cellulitis is to practice good wound care and to seek medical attention if symptoms arise.  Wounds should be cleaned properly and bandaged to prevent infection. 

Bandages should be changed daily or if they become dirty or wet.  If there is any concern about retained foreign bodies, medical attention should be sought.  If there is a fever and the infection appears to be spreading medical attention should be sought immediately.