Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT PART 6-33: INFECTIOUS ERYTHEMAS + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Edematous, expanding, erythematous, warm plaque with or without vesicles or bullae Lower leg is frequently involved Pain, chills, and fever are commonly present Septicemia may develop +++ General Considerations ++ Usually due to gram-positive cocci, though gram-negative rods or even fungi can produce similar picture The major portal of entry for lower leg cellulitis is toe web tinea pedis with fissuring of the skin at this site Erysipelas is a superficial form of cellulitis that occurs classically on the cheek, caused by β-hemolytic streptococci (see Erysipelas) + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Lesion begins as a small batch and expands over hours Edematous, expanding, erythematous, warm plaque with or without vesicles or bullae Pain at the lesion, malaise, chills, and moderate fever Usually on the lower leg Lymphangitis and lymphadenopathy may be present Progressive chills, fever, and malaise Septicemia and septic shock may develop +++ Differential Diagnosis ++ Deep venous thrombosis Venous stasis Candidiasis Anthrax Contact dermatitis Herpes zoster (shingles) Scarlet fever Angioedema Necrotizing fasciitis Sclerosing panniculitis Underlying osteomyelitis Systemic lupus erythematosus Erysipeloid + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ Attempts to isolate the responsible organism by injecting and then aspirating saline are successful in 20% of cases Leukocytosis and an increased sedimentation rate are almost invariably present but are not specific Blood cultures may be positive Skin biopsy is particularly helpful in an immunocompromised patient whose cellulitis may be due to an uncommon organism +++ Diagnostic Procedures ++ ALT-70 is a predictive model to diagnose cellulitis or a cellulitis mimic and to provide guidance about when a dermatology consultation is needed Variables are Asymmetry (3 points) Leukocytosis of 10,000/mcL or more at presentation (2 points) Tachycardia above 90 beats per minute (1 point) Age 70 years or older (1 point) Score above 5 carries more than an 82% chance of a true cellulitis while a score below 2 suggests a greater than 83% chance of a cellulitis mimicker + Treatment Download Section PDF Listen +++ +++ Medications ++ Intravenous or parenteral antibiotics effective against group A β-hemolytic streptococci and staphylococci may be required for the first 24–48 hours Dicloxacillin or cephalexin, 250–500 mg four times daily orally for 5–10 days, is usually adequate for mild cases or following initial parenteral therapy In patients in whom intravenous treatment is not instituted, the first dose of oral antibiotic can be doubled to achieve rapid high blood levels Oral penicillin 250 mg twice daily or oral erythromycin 250–500 mg twice daily can decrease the risk of recurrence in patients with recurrent lower leg cellulitis (three to four episodes per year) + Outcome Download Section PDF Listen +++ +++ Prevention ++ Measures to prevent recurrences include Compression Treating toeweb intertrigo and tinea pedis Controlling venous insufficiency +++ Prognosis ++ The rare infective endocarditis due to E rhusiopathiae may have mortality rates as high as 30–40% despite surgery, even in immunocompetent individuals +++ When to Refer ++ If there is a question about the diagnosis, if recommended therapy is ineffective, or if specialized treatment is necessary +++ When to Admit ++ Severe local symptoms and signs Signs of sepsis Elevated white blood cell count of 10,000/mcL or more with marked left shift Failure to respond to oral antibiotics + References Download Section PDF Listen +++ + +Dalal A et al. Interventions for the prevention of recurrent erysipelas and cellulitis. Cochrane Database Syst Rev. 2017 Jun 20;6:CD009758. [PubMed: 28631307] + +Klotz C et al. Adherence to antibiotic guidelines for erysipelas or cellulitis is associated with a favorable outcome. Eur J Clin Microbiol Infect Dis. 2019 Apr;38(4):703–9. [PubMed: 30685804] + +Ko LN et al. Clinical usefulness of imaging and blood cultures in cellulitis evaluation. JAMA Intern Med. 2018 Jul 1;178(7):994–6. [PubMed: 29610842] + +Miller LG et al; DMID 07-0051 Team. Clindamycin versus trimethoprim-sulfamethoxazole for uncomplicated skin infections. N Engl J Med. 2015 Mar 19;372(12):1093–103. [PubMed: 25785967] + +Patel M et al. The red leg dilemma: a scoping review of the challenges of diagnosing lower limb cellulitis. Br J Dermatol. 2019 May;180(5):993–1000. [PubMed: 30422315] + +Quirke M et al. Risk factors for nonpurulent leg cellulitis: a systematic review and meta-analysis. Br J Dermatol. 2017 Aug;177(2):382–94. [PubMed: 27864837] + +Raff AB et al. A predictive model for diagnosis of lower extremity cellulitis: A cross-sectional study. J Am Acad Dermatol. 2017 Apr;76(4):618–25. [PubMed: 28215446] + +Raff AB et al. Cellulitis: a review. JAMA. 2016 Jul 19;316(3):325–37. [PubMed: 27434444] + +Stevens DL et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014 Jul 15;59(2):147–59. [PubMed: 24947530] + +Tay EY et al. Cellulitis Recurrence Score: a tool for predicting recurrence of lower limb cellulitis. J Am Acad Dermatol. 2015 Jan;72(1):140–5. [PubMed: 25443627]