Derm Infections (LG3) -Patel Flashcards
What are some predisposing factors for infection?
- minor trauma
- preexisting skin disease
- poor hygiene
What skin disease has intra-epidermal cleavage below and within the stratum granulosum resulting in bulla formation? Which pathogen causes this?
- Impetigo (contagious superficial skin infection)
- S. aureus producing epidermolytic exotoxins cleaves desmoglein 1
What titer will be elevated after GAS impetigo? What type of lesions will this have?
- Anti-DNAse B titer
- non-bullous impetigo –> honey-colored crust
What are the complications of GAS impetigo in children? What should you order if you suspect this complication?
- post-streptococcal glomerulonephritis 1-5 weeks after the infection is commonly seen in children <5
- Order the DNAse B titer if suspect (negative titer does not r/o GAS)
What is erysipelas? What is the most common cause? What is the treatment?
- Superficial form of cellulitis with dermal lymphatic vessels→ edematous skin lesion with DISTINCT RAISED BORDERS
- Most common: Group A beta hemolytic streptococcus
- Tx: PCN
What type of borders does cellulitis have?
ill-defined borders
expanding erythematous plaque with ill-defined border, which is tender to palpation, warm to touch
What causes SSSS (Staphylococcal scalded skin syndrome)?
- staphylococcus exfoliative toxins → spread in bloodstream→ cause intraepidermal splitting by cleavage of desmoglein 1 → wrinkles → transient bullae→ peels off in large sheets leaving a moist, red, glistening surface
- NOT culturable because caused by exotoxins
What is the treatment for outpatient non-purulent cellulitis?
treat for Group A strept
PCN
What is the treatment for outpatient purulent cellulitis?
empirically cover community acquired MRSA
What is the treatment for hospitalized cellulitis?
cover MRSA and culture if purulent
What causes the pain associated with acute zoster and postherpetic neuralgia?
injury of the peripheral nerves and altered CNS signal processing
What do molluscum look like?
2 to 5- mm smooth pink, or flesh-colored, dome-shaped, umbilicated papules with a central keratotic plug (black dot)
What is an exanthem? What is this generally due to?
-When an infection causes an ill person to break out in a rash that covers most of the body, the rash is called an exanthem or an eruption.
viruses causing these are due to:
- immune responses
- replication in the vasculature and leakage of serum into surrounding tissue
What is a concerning complication of measles?
SSPE =encephalitis
