Bacterial disease Flashcards
What organism causes bacillary angiomatosis?
Bartonella henselae
What percent of people with bacillary angiomatosis recall some bite or scratch?
Only 20%
How are rickettsial organisms transmitted?
Arthropod is host/vector (ticks, fleas, lice, and mites)
What two rickettsial diseases don’t have eschar?
Rocky Mountain spotted fever and typhus group
The differential diagnosis for lesions with eshcar?
Ecthyma gangrenosum, pyoderma gangrenosum, ecthyma/ulcerating impetigo, rickettsiosis, non-rickettsiosis (anthrax, barnella, tularensis, trachomatis, etc), non-infectious
What is the pneumonic and diseases with sporitrichoid spread?
Cat scratch disease Atypical mycobacteria Tuberculosis Nocardia Sporotrichosis Phaeophyphmycoses Leishmaniasis Anthrax Tularemia
Is impetigo contagious?
Yes, direct person to person contact or through fomites is how it is spread
Types of impetigo?
Non-bullous (70%) and bullous (30%)
Most common organism for non-bullous impetigo?
S. aureus > strep pyogenes
Most common location for impetigo?
It is often seen in children and it is often seen on the face, perioral/perinasal areas
Most common organisms for bullous impetigo?
Phage group II (types 55 and 71) staph aureus
What is the pathophysiology of bullous impetigo?
The phage group II staph produce exfoliatoxins A and B which cleaves desmoglein 1 and leads to subcorneal/intragranular acantholysis
What is the distribution of bullous impetigo compared with non-bullous impetigo?
The bullous form is more generalized. Like the non-bullous from it is more common in children
The appearance of bullous impetigo lesions?
early on: small vesicles enlarge into 1-2 cm superficial bullae late: flaccid, transparent bullae measuring up to 5cm in diameter; after rupture, there is a collarette of scale, but no thick crust, little surrounding erythema
Is the risk of acute post-streptococcal glomerulonephritis affected by treatment of impetigo w/ antibx?
No, risk same if caused from strep even w/ tx
What is the most common causative organism of bacterial folliculitis?
S. Aureus folliculitis
Most common location of s. aureus folliculitis?
face or beard area
What is sycosis barbae?
Large red papulopustules with or without plaques and small pustules
What is the major risk factor for pseudomonal folliculitis?
Poorly chlorinated hot tubs/whirlpools
Treatment for staph folliculitis?
Chlorhexidine washes or sodium hypochlorite (.5cups of bleach in a full 40-gallon bathtub or .5-1 tsp per gallon in a spray bottle
if it is widespread can do a beta lactam antibx
Tx for gram-negative folliculitis?
isotretinoin
Tx for pseudomonal folliculitis?
self-resolves, but can give cipro if severe
What is the difference between abscess vs furuncle vs carbuncle?
Abscess are inflamed and fluctuant nodule that can arise anywhere. Furuncle: only occurs with hair follicles on hair-bearing sites, often the head and neck > intertriginous zones, thighs or other sites of friction. Carbuncle: a collection of furuncles, often deeper with multiple draining sinuses. Most often on the posterior neck, back and thighs and systemic sx’s can occur in these.
Which of the 3, furuncle, abscess or carbuncle is MRSA most commonly associated with?
Most commonly associated with furunculosis, often mistaken for a spider bite. Can be associated with cellulitis and necrotic plaques?