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Bacterial Infections

»	Which bacterium is the most common cause of skin infections?
»	What kinds of skin infections does Staphylococcus aureus produce?
»	Is Staphylococcus aureus the only bacterium that causes impetigo?
»	What does staphylococcal impetigo look like?
»	Why is staphylococcal impetigo frequently bullous?
»	How is bullous impetigo diagnosed?
»	How is bullous impetigo treated?
»	What is the difference between a furuncle and a carbuncle?
»	How do furuncles present?
»	What is the best way to treat furuncles?
»	Why do some patients develop recurrent staphylococcal impetigo or recurrent furunculosis?
»	How is staphylococcal carriage eliminated?
»	What is staphylococcal scalded-skin syndrome?
»	Describe the presentation of toxic shock syndrome.
»	Why is S. aureus frequently found in secondary infections of dermatitis and wounds?
»	What is MRSA?
»	What is the difference between HA-MRSA and CA-MRSA?
»	What types of cutaneous infections are produced by b-hemolytic streptococci?
»	How does streptococcal impetigo present?
»	What is ecthyma?
»	What is blistering distal dactylitis?
»	What is erysipelas?
»	How do you diagnose erysipelas?
»	How is erysipelas treated?
»	Describe the cutaneous manifestations of Lyme disease.
»	A patient living in an endemic area for Lyme disease reports a history of a tick bite. Should that patient receive antibiotic prophylaxis?
»	What types of skin infections does Pseudomonas aeruginosa produce?
»	How does ecthyma gangrenosum differ from ecthyma?
»	Where do you usually acquire Pseudomonas folliculitis?
»	How does Pseudomonas folliculitis present?
»	What is the best treatment for Pseudomonas folliculitis?
»	How is Wood’s light used in diagnosing Pseudomonas infections?
»	What causes tularemia? Where did the name tularemia come from?
»	Describe the skin lesions of tularemia.
»	How should tularemia be treated?
»	What is trichomycosis axillaris?

Why is staphylococcal impetigo frequently bullous?

Bullous impetigo is caused by staphylococci that produce toxins (exfoliative toxins A and B) capable of causing the split in the epidermis by targeting the epidermal adhesion molecule, desmoglein 1 (Dsg-1).

Group II staphylococci are most commonly implicated. Hanawaka Y, Stanley JR: Mechanisms of blister formation by staphylococcal toxins, J Biochem 136:747–750, 2004.