Dermatology
Bacterial Diseases
Built from Dermatology, 5th Edition

What’s inside
11 sections · 136 slides
The Skin's Bacterial World
Why bacteria cause disease here, and how deep an infection goes decides its name
- What lives on our skin
- Bacterial makeup of normal skin by body site
- How bacterial skin infections get their names
- How deep an infection sits changes its name
Impetigo
The most common bacterial skin infection in children
- What is impetigo
- Who gets impetigo, and when
- How non-bullous impetigo develops
- How bullous impetigo develops
- How impetigo looks
- What impetigo looks like under the microscope
- Characteristic features of non-bullous impetigo
- Characteristic features of non-bullous impetigo (continued)
- Characteristic features of bullous impetigo
- How impetigo is diagnosed
- Most common mimics of impetigo
- Less common mimics of impetigo
- Treating impetigo
- Empiric treatment of cutaneous staphylococcal and streptococcal infections in adults
- Empiric treatment of cutaneous staphylococcal and streptococcal infections in adults (continued)
Folliculitis, Furuncles, and Carbuncles
Infection that starts in a single hair follicle can spread to a whole cluster
- What is bacterial folliculitis
- Who gets folliculitis, and how it looks
- Diagnosing and treating folliculitis
- Clearing the S. aureus carrier state
- Abscesses, furuncles, and carbuncles
- Risk factors and where furuncles occur
- How furuncles and carbuncles look
- How furuncles look under the microscope, and diagnosis
- Treating furuncles and carbuncles
Methicillin-Resistant Staphylococcus Aureus
A drug-resistant staph strain behind most purulent skin infections seen in emergency departments
- What is MRSA
- Community-associated MRSA (CA-MRSA)
- Community-associated MRSA (CA-MRSA) (continued)
- Healthcare-associated MRSA (HA-MRSA)
- Healthcare-associated MRSA (HA-MRSA) (continued)
- MRSA and the ESKAPE pathogens
- The ESKAPE pathogens
- How MRSA presents
- How MRSA becomes drug-resistant
- Three ways staph resist macrolides and clindamycin
- Hidden (inducible) clindamycin resistance
- How the D-test detects hidden resistance
- Diagnosing and treating MRSA
Toxin-Mediated Staphylococcal and Streptococcal Disease
When a bacterial toxin spreads beyond the local infection, disease becomes widespread
- Blistering distal dactylitis
- Treating blistering distal dactylitis
- What is ecthyma
- How ecthyma looks, and its risk factors
- Clinical features of ecthyma
- Clinical features of ecthyma (continued)
- What is staphylococcal scalded skin syndrome (SSSS)
- Who gets SSSS
- How SSSS looks
- SSSS: course, biopsy, and diagnosis
- Comparison of toxic epidermal necrolysis (TEN) and SSSS
- Treating SSSS
- What is toxic shock syndrome (TSS)
- How the TSS toxin causes disease (superantigens)
- From superantigen to shock
- How staphylococcal TSS looks
- Case definition of staphylococcal toxic shock syndrome
- Case definition of streptococcal toxic shock syndrome
- Treating staphylococcal TSS
- What is scarlet fever
- How scarlet fever looks
- Diagnosing and treating scarlet fever
- What is streptococcal toxic shock syndrome
- The superantigen-receptor interaction
- How streptococcal TSS presents
- Toxic shock syndromes: staphylococcal versus streptococcal
- Treating streptococcal TSS
Streptococcal Skin and Soft Tissue Infections
From a sharply marginated red plaque to a deep, spreading infection of the skin
- What is erysipelas
- Who gets erysipelas
- How erysipelas looks
- Erysipelas under the microscope, and diagnosis
- Causes of "pseudocellulitis"
- Causes of "pseudocellulitis" (continued)
- Treating erysipelas
- Streptococcal intertrigo
- Perianal and vulvovaginal streptococcal infection
- Erysipelas, streptococcal intertrigo, and perianal streptococcal disease
- What is cellulitis
- Who gets cellulitis, and how it starts
- How cellulitis looks
- Cellulitis under the microscope
- Diagnosing cellulitis
- Approach to the patient with cellulitis
- Cellulitis look-alikes ("pseudocellulitis")
- Pseudocellulitis: clinical examples
- Treating uncomplicated cellulitis
- Severe cellulitis, and prevention
Deep and Necrotizing Soft Tissue Infections
Infections that reach muscle and fascia move fast and can be fatal without early surgery
- Pyomyositis: infection of skeletal muscle
- What is botryomycosis
- How botryomycosis looks and is diagnosed
- Botryomycosis under the microscope
- What is necrotizing fasciitis
- Necrotizing fasciitis: four types by cause
- Who gets necrotizing fasciitis
- How necrotizing fasciitis looks
- Diagnosing necrotizing fasciitis
- Assessing and treating suspected necrotizing fasciitis
- Treating necrotizing fasciitis
- Clostridial skin infections: gas gangrene's family
- Recognizing a clostridial infection
- Clostridial anaerobic cellulitis
- Clostridial anaerobic cellulitis (continued)
- Clostridial anaerobic cellulitis (continued)
- Clostridial anaerobic cellulitis (continued)
- Clostridial myonecrosis (gas gangrene)
- Clostridial myonecrosis (gas gangrene) (continued)
- Clostridial myonecrosis (gas gangrene) (continued)
- Clostridial myonecrosis (gas gangrene) (continued)
Staphylococcal Bacteremia and Endocarditis
How bloodstream staph infection shows up in the skin
- Staph bacteremia and its skin signs
- Skin clues to staphylococcal endocarditis
Corynebacterial Skin Infections
Gram-positive rods that make up nearly half the skin's normal bacteria
- Corynebacteria: mostly harmless, occasionally not
- What is erythrasma
- How erythrasma looks
- Diagnosing and treating erythrasma
- What is pitted keratolysis
- How pitted keratolysis looks
- Trichomycosis: infected hair shafts
- What is cutaneous diphtheria
- How cutaneous diphtheria looks
- Diagnosing and treating cutaneous diphtheria
Other Gram-Positive Skin Infections
From a biological-weapon threat to a fish-handler's rash
- What is cutaneous anthrax
- A brief history of anthrax
- How anthrax causes disease
- Cutaneous anthrax: clinical timeline
- More clues to cutaneous anthrax
- Diagnosing and treating anthrax
- Bacillus cereus infection
- What is erysipeloid
- How erysipeloid looks
- Listeriosis and its skin signs
Looking Ahead to Gram-Negative Bacteria
Where this chapter's Gram-positive story hands off
- From Gram-positive to Gram-negative skin infections
- Uncommon Gram-negative infections that present with fever and skin findings
- Key points to take away
- References
- Dermatology, 5th Edition (2-Volume Set)