Cellulitis is an acute inflammatory condition of the skin that is characterized by localized pain, redness, swelling, and rise in temperature of that particular area of inflammation. The commonest organisms that cause cellulitis are staphylococcus and streptococcus and they being the commonest organism, the treatment is generally targeted at killing these organisms.
The primary treatment (first line treatment) of cellulitis:
The first line treatment of cellulitis is with newer penicillin. Among newer penicillins Nafcillin or oxacillin at the dose of 2 gram intravenously every 4 to 8 hourly is the drug of choice.
Second line treatment of cellulitis:
Second line treatment of cellulitis is with cephalosporins, other semi-synthetic penicillins or with drugs like erythromycin. Among cephalosporins the drug of choice is Cefazolin, (dose 1 to 2 gram every 8 hourly). Ampicillin + sulbactam (semisynthetic penicillin) or Erythromycin, 0.5 to 1.0 gram intravenously every 6 hourly or Clindamycin, 600–900 mg intravenously every 8 hourly can also be used as second line drug for treatment of cellulitis.
The resistance to antibiotics like erythromycin is a problem in treatment of infections like cellulitis. The frequency of erythromycin resistance in group A Streptococcus is very common and currently approximately 5% in the United States but has reached as high as 70% to 100% in many countries. Most (though not all), erythromycin-resistant group A streptococci are susceptible to clindamycin. Approximately 90% to 95% of Staphylococcus aureus (which also cause cellulitis) strains are sensitive to clindamycin.
Cellulitis is a common clinical problem. Cellulitis is an acute inflammatory condition of the skin, generally caused by infection. The typical characteristic features of Cellulitis are localized pain, erythema (redness), swelling, and heat at the area of inflammation.
Causative agents of Cellulitis:
Cellulitis can be caused by indigenous flora which colonizes the skin and appendages like Staphylococcus aureus and Streptococcus. Pyogenes. Other species of staphylococcus and streptococcus also cause cellulites. It can also be caused by variety of other exogenous organisms, mainly bacteria like Pseudomonus aeruginosa, Pasteurella multocida (commonly cat bite and less commonly dog bite), Capnocytophaga canimorsus, Eikenella corrodens, Aeromonas hydrophila etc.
Route of entry of causative organism in Cellulitis:
Bacteria generally gain access to the epidermis through cracks in the skin, which is mainly due to abrasions, cuts, burns, insect bites, surgical incisions, and intravenous catheters. Different organisms gain entry by different routes, e.g. cellulitis caused by S. aureus spreads from a central localized infection, like an abscess (folliculitis), or from an infected foreign body like a splinter, a prosthetic device, or an intravenous catheter.
Diagnosis of cellulites:
Due to the involvement of exogenous bacteria in cellulites, a thorough history including epidemiologic data can provides important clues to the infecting organism. Whenever possible, a Gram’s stain and culture of the pus which is collected during drainage can provide a definitive diagnosis. If pus can not be cultured or Gram’s stain can not be done, it is very difficult to establish a diagnosis due to the similarity of the clinical features in staphylococcus and streptococcus cellulitis. Even with needle aspiration of the leading edge or a punch biopsy of the cellulitis tissue itself, cultures are positive in only 20% of cases, which suggest only small numbers of bacteria cause cellulites. The expanding area of redness within the skin may be a direct effect of extra-cellular toxins or due to the soluble mediators of inflammation.