Cellulitis

Erysipelas

Cellulitis can involve any area of the body, lower extremity is most common. Erysipelas is associated with marked swelling of the skin and does not involve subcutaneous tissues. Risk factors: Disruption of the cutaneous barrier Venous or lymphatic compromise Previous history of cellulitis

MICROBIOLOGY Cellulitis in the majority of patients is caused by beta- hemolytic streptococci, including groups A, B, and, less often, C, and G. Staphylococcus aureus is also common.

Differential Diagnosis Contact dermatitis Insect stings Drug reactions Foreign body reactions Lymphedema Gouty arthritis Uncommonly: urticaria, lupus, sarcoidosis, lymphoma, leukemia, Paget disease, and panniculitis.

Treatment The 2005 Infectious Diseases Society of America (IDSA) guideline: penicillinase-resistant semisynthetic penicillin or a 1st generation cephalosporin (Cefazolin) Vancomycin for those patients with severe infection particularly those infections associated with necrosis.

PCN allergy: Clindamycin Vancomycin Oral therapy: Cephalexin, Dicloxacillin, Fluoroquinolones Duration of therapy — The usual duration of antimicrobial therapy is 10 to 14 days.

Special Situations Fresh water - Aeromonas species →Ciprofloxacin + Cefazolin Salt water - Vibrio vulnificus →Tetracyclines Hot tub exposure - Pseudomonas aeruginosa Cat bites - Pasteurella multocida →penicillin + beta-lactamase inhibitor (Augmentin)