A middle aged patient came to the office the other day with complaints of "cellulitis."  The patient explained that he had two prior incidents of cellulitis, one of which required IV antibiotics and hospitalization for three days.  The cellulitis has always occurred in the same leg.  The patient stated that he noticed a small scratch on his left leg a few days prior.  The leg became swollen, red and warm over the next few days.  He came to the office knowing that he needed antibiotic treatment 4 days prior to his current visit.  The patient had been placed on levaquin(a fluoroquinolone) "since he was allergic" to keflex(a cephalosporin) and would develop "hives and blisters".

The patient denied any history of diabetes, immunodeficiencies, vascular disorders, or previous leg surgeries.  The only medication the patient was taking was the Abx.  The patient's ROS was negative.  On physical exam the patient was morbidly obese, afebrile, VSS.  The left lower extremity was remarkable being erythematous, dry, warm and exhibiting 4+ pitting edema.  The erythema and edema were distributed from the ankle to about 2/3 up the left leg.  There were two fine superficial lacerations on the anterior leg.  There were no signs of bullae or necrosis.  The leg was nontender with palpation.  The line which had been drawn on the patient's leg his previous visit as the top most border of the erythema continued to demarcate the site of inflammation.  There was no sign of improvement.  The patient's other LE exhibited no edema, no erythema, and no dryness.  Here is a picture of bilateral LE cellulitis. 

Points to note in the history when evaluating cellulitis:

• Hx of trauma or surgery - none reported by this patient
• Hx of peripheral vascular disease or diabetes - neither were positive in this patient
• Hx of foreign body - none reported by this patient

4 cardinal signs of infection: erythema, pain, swelling, and warmth.

Most Common Causes of Cellulitis in a healthy individual:  Streptococcus pyogenes and S aureus

Workup:  Most often lab studies, imaging, and procedures are unnecessary and none were done for this patient.  You can actually rely on your H&P!

Treatment:  Often cellulitis without systemic symptoms as was seen in this patient can be treated in the outpatient setting with a 10 day course of an appropriate oral antibiotic.  This patient was treated with levaquin, which according to these two sources(one and two) works with uncomplicated cellulitis.  However, without any signs of improvement after 4 days of Abx, this patient was advised to go to the ER for possible admission and IV antibiotics. 

It is recommended that patients follow up 2 days after initial treatment of the oral antibiotic to assess improvement, and if none - parenteral Abx should be initiated.        

Prognosis:  "Uncomplicated cellulitis has an excellent prognosis. Outpatient regimens are effective in far more than 90% of patients. Of those who fail outpatient therapy or require admission initially, intravenous antibiotics are very effective."

Points specific to this case:  This patient has no history of a vascular disorder, or diabetes despite being morbidly obese.  Additionally, this patient has had three episodes of cellulitis in the same leg.  Most likely, this patient has some issue which is predisposing him to cellulitis and has not yet been diagnosed. 

The helpful links:

http://www.fpnotebook.com/ID159.htm

http://www.fpnotebook.com/ID157.htm

  http://www.fpnotebook.com/ID142.htm

http://www.fpnotebook.com/ID141.htm

http://www.emedicine.com/emerg/topic88.htm

http://www.emedicine.com/med/topic310.htm

http://www.sma.org/smj1997/decsmj97/6text.htm

http://www.healthscout.com/rxdetail/68/58/7/main.html

http://www.amcstudents.com