Snapshot A 60-year-old man with a past medical history of diabetes and hypertension presents with swelling in his right leg after he scraped his calf on the corner edge of his coffee table. On physical exam, there is a poorly demarcated 10 cm red and tender plaque on his right calf. Some parts resemble an orange peel. There is a superficial scrape in the middle of the plaque. He is sent home on oral antibiotics. Introduction Clinical definition painful bacterial infection involving the deeper dermis and subcutaneous tissues often from Streptococcal spp. or, less commonly, S. aureus from superficial involvement of skin to deep impetigo (very superficial skin infection) erysipelas (upper dermis and cutaneous lymphatics) cellulitis (deeper dermis and subcutaneous tissues) Pathogenesis pre-existing injury in skin can act as entry portal for bacteria Epidemiology incidence 48 per 1000 person-years risk factors skin ulcers tinea pedis intravenous drug use venous insufficiency diabetes lymphedema pre-existing skin injury Etiology streptococcus species S. aureus Presentation Symptoms painful and tense skin Physical exam fever diffuse inflammation of affected area poorly demarcated red warm tender dimpling around hair follicles resembling orange peel (peau d’orange) may have purulence Evaluation Labs tissue cultures may aid diagnosis and guide treatment blood cultures if cellulitis is purulent Diagnosed clinically Differential Erysipelas more superficial involvement of skin and soft tissues there is often an overlap and may not be distinguished clinically from erysipelas Treatment Medical oral antibiotics indications for mild cases of cellulitis drugs penicillin dicloxacllin cephalexin clindamycin for suspected methicillin-resistant S. aureus IV antibiotics indications for cellulitis with signs of systemic infection e.g., positive blood cultures drugs penicillin cefazolin ceftriaxone clindamycin Complications Skin abscess formation more common in IV drug users Lymphedema due to lymphatic damage caused by infection may be permanent Sepsis Prognosis Recurrence
QUESTIONS 1 of 1 1 Previous Next (M3.DM.15.2) A 34-year-old man is seen by his primary care physician for a swollen and red leg. He denies any acute injury to his leg but did recently return from a trip to China. His temperature is 97.0°F (36.1°C), blood pressure is 133/80 mmHg, pulse is 82/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for the finding in Figure A. An ultrasound of the lower extremity is performed as seen in Figure B without any change in appearance of the ultrasound when there is compression. Which of the following is the best next step in management? QID: 103600 FIGURES: A B Type & Select Correct Answer 1 Cephalexin 44% (7/16) 2 Heparin 19% (3/16) 3 Incision and drainage 6% (1/16) 4 Piperacillin-tazobactam 12% (2/16) 5 Vancomycin 0% (0/16) M 11 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic