Lecture 3: Infections Flashcards
MCC of bullous impetigo
Staph Aureus & GAS
Both MSSA and MRSA (GAS and as)
Results in scalded skin syndrome
MC demographic for bullous impetigo
Newborn and older infants
bullies and babies
MC demographic for non-bullous impetigo
All ages
Presentation of non-bullous impetigo
- Painful and tender
- Erosions with crusts
- 1-3 cm lesions
- Central healing
- Regional LAN
- Scattered, discrete lesions
What is autoinoculating?
Kid scratches vesicle, spreads to a different area.
Presentation of bullous impetigo
- No erythema
- Vesicles => bullae
- Yellow => dark brown
- negative Nikolsky sign
Collapse of bullae in 1-2d
How is bullous impetigo dx?
Clinically, BUT often use Gram stain & culture
Tx of impetigo
- Warm water soaks followed by topical mupirocin
- 7d abx for widespread (keflex or erythromycin)
- MRSA = doxy
- Critically ill with MRSA = vanco or linezolid
- Bullous or severe = PO
Patient education for impetigo
- Good hygiene
- Mupirocin in any skin breaks
- Avoid contact with others in first 24h of abx use
- BPO wash
- Ethanol or isopropyl gel for hands
BPO = benzoyl peroxide
How soon should you f/u for impetigo?
1 week
First line systemic tx for impetigo
- Systemic: dicloxacillin/augmentin/cephalexin
- If PCN allergic: macrolides
dicey IM
Define folliculitis
Infection of hair follicle +/- pus in the ostium of the follicle
What does folliculitis become if it progresses? Most common organisms?
- Becomes abscesses or furuncles
- Staph, Pseudomonas hot tub, Viral , fungal, syphilis
How is folliculitis dx?
- Clinical, but it can be confirmed with
- Gram stain
- C&S
- KOH if fungal suspected
Tx of folliculitis
- Mild: warm compresses, BPO wash
- Moderate: topical abx = clinda or mupirocin
- Severe MSSA: Keflex
- Severe MRSA: Doxy or bactrim x10d
almost all superficial MRSA seems to be doxy
What are the typical causative organisms for an abscess related to folliculitis?
MSSA or MRSA
When is abx therapy indicated for an abscessed folliculitis?
- Single >= 2cm
- Multiple
- Surrounding cellulitis
- Immunosuppression and other comorbidities
- S/S toxicity
- Inadequate response
- Indwelling medical device
- High risk of transmission
When is surgery considered for I&D?
- Very large
- Located on palms (nerves?)
- Soles (nerves?)
- Nasolabial areas
- Genitalia
What is a furuncle?
Acute, deep seated, red, hot, tender nodule or abscess
Presentation of a furuncle
- Nodule with cavitation after drainage
- Staphylococcal folliculitis
- Any hair bearing region
Management of a furuncle
- Warm compresses
- Erythema = need abx
- Bactrim
- Clinda
- Doxy
7d take the car of uncles to BCD
What is a carbuncle?
Deeper connection of interconnected furuncles
A car of furuncles
MC location for carbuncles
- Nape of neck
- Back
- Thighs
trunk of the car
Management of uncomplicated carbuncle
- Bactrim
- Clinda
- Doxy
7d take the car of uncles to BCD
When to admit for carbuncle and DOC?
- Toxic
- Rapid progression
- No improvement after 24-48h of PO ABX
- DOC: Vanco 1-2g IV daily
Deep = vanco
What is necrotizing fasciitis?
- Flesh eating disease
- Rapid progression of infection with extensive necrosis of soft tissues and overlying skin
MCC of necrotizing fasciitis?
- GABHS
- Pseudomonas
- Clostridium
Polymicrobial
MC demographic and risk factors for necrotizing fasciitis?
- Middle aged 30-40s
- DM, ETOH abuse, Liver dz, CKD, malnutrition
Often begins with non-penetrating minor trauma
Presentation of necrotizing fasciitis
- Severe pain out of proportion
- Skin hyperthesia
- Cyanosis
- Skin pallor
- Muscle weakness
- Foul smelling exudate
As necrotizing fasciitis develops, what does it appear as?
- Cyanotic
- Vesicle and bullae appearance
- Black eschar with surrounding irregular border
- Fever and systemic symptoms
Clinical red flags for necrotizing fasciitis?
- Severe, constant pain out of proportion to PE
- Erythema turning into dusky gray
- Malodorous, dirty dishwater discharge
- Gas in the soft tissues
- Edema beyond erythema
- Rapid progression
Tx of necrotizing fasciitis
- Debridement
- Broad spectrum ABX: carbapenem, unasyn, clinda, vanco for MRSA, all depends on gram stain and C&S
What is erysipelas?
Acute, superficial infection of the dermis and dermal lymphatic vessels
MC demographic and etiology of erysipelas?
- GABHS
- MC in young children or older adults
How does erysipelas present?
- Prodrome of fever, chills, anorexia, malaise
- General signs of sepsis potentially
- Lesions that are painful/tender/hot, bright, red, edematous plaques with sharp borders