Bacterial infections Flashcards
Summarise the pathogenesis of impetigo
Common in school aged children
Caused by either/or combination of staph aureus or strep pyogenes
Strep pyogenes = socioeconomically disadvantaged people, aboriginal and Torres Strait islander people
What are some predisposing factors to impetigo?
Hot/humid climates
Poor hygiene
skin trauma
diabetes
immunocompromised
What is the clinical presentation of bullous impetigo?
Common in newborns
Vesicles rupture and crust
single or multiple lesions w/in 24-48 hrs
around nose and mouth
What is the clinical presentation of non-bullous impetigo?
Most common
Distinct yellow crusting lesions, can itch
involves face and extremities
What bacteria causes bullous impetigo?
S. aureus
Large fluid filled vesicles
What bacteria causes non-bullous impetigo?
Staph and strep
small pustules
What are some general signs/sx of impetigo?
Sores that can be itchy, occasionally painful
Begins as small cuts, insect bites, broken skin from eczema scratching
What are some differential diagnoses to impetigo?
Tinea = impetigo is more rapid over several days, tinea is not really crust/weepy
Allergic dermatitis = more intense itch, will not improve w/ abx, may have distinctive shape
Summarise the pathogenesis of folliculitis
Infection, blockage, irritation to hair follicle –> inflammatory reaction
What can folliculitis be caused by?
Too frequent application of creams/ointments
Shaving (ingrown hairs), heavy sweating, macerations
What are the sx of folliculitis?
Small red micropapule around hair follicle
develops into pustule over 48 hrs
Single or many
mild pain or discomfort
Summarise the classifications of folliculitis
Bacterial folliculitis = S. aureus (common), P. aeruginosa, dermatophytes, HSV
Superficial folliculitis = inc bact (S. aureus), hot tubs, razor bumps, and/or yeast infections
- tender red spot at hair follicle, small surface pustule
Deep folliculitis = entire hair follicle, severe sx, can cause painful boils
What are some differential diagnoses for folliculitis?
Tinea
Rosacea
Acute urticaria
Candidiasis
Drug interaction w/ eosinophilia and systemic sx (DRESS) syndrome
What is the topical treatment for impetigo in non-remove areas?
Topical antibiotics for localised sores
Mupirocin 2% ointment, q8hr 5/7
What is the systemic treatment for impetigo in non-remove areas?
Indicated if multiple sores/recurrent infections occur
Di/flucloxacillin = q6h 7/7
Cephalexin (q6h or q12h = 7/7) OR trimethoprim+sulfamethoxazole (q12h for 3 days or daily for 5/7)
