« Back to Infections and Infestations

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?

 
 
 

What is erysipelas?


Characteristic lesion of erysipelas demonstrating indurated, erythematous plaque with sharply demarcated border.
Fig. 27.7 Characteristic lesion of erysipelas demonstrating indurated, erythematous plaque with sharply demarcated border.
Erysipelas, or St. Anthony’s fire, is a form of cellulitis usually caused by b-hemolytic streptococci, rarely by Staphylococcus aureus. Patients often
Streptococcal cellulitis that started with an injury to the index finger. Note associated lymphangitis extending up the arm.
Fig. 27.8 Streptococcal cellulitis that started with an injury to the index finger. Note associated lymphangitis extending up the arm.
have a prodrome of malaise, fever, and headache. Typically, erysipelas presents on the face as an erythematous indurated plaque with a sharply demarcated border and a “cliff-drop” edge (Fig. 27-7). In severe cases, the epidermis may become bullous, pustular, or necrotic. Untreated erysipelas can be fatal due to vascular thrombosis, bacteremia, or toxin release. Streptococcal cellulitis is a more generic term that includes erysipelas but also cellulitis that lacks the characteristic cliff-drop border. Known commonly as “blood poisoning,” it is most often found on extremities and is associated with lymphangitis (Fig. 27-8).