Bacterial Skin Infections Flashcards
What does impetigo look like?
multiple erythematous, honey crusted lesions around nose and mouth. some vesicles.
what bacteria cause bacterial impetigo?
1) Staphylococcus aureus
2) Streptococcus pyogenes
What are the two types of impetigo
- bacterial (70%)
- bullous
What is the epidemiology of impetigo?
- most commonly found in preschool children
- more common in hot areas / late summer
What is the distribution of bullous impetigo?
small / large bullae on the face, trunk, extremeties, buttocks - fluid inside initially clear, then becomes cloudy and bursts to form honey crusted lesions.
What is the treatment for impetigo?
- usually self limiting but speed process to avoid complications
- topical mupirocin or fusidic acid
- oral flucloxacillin or erythromycin
What is the likely cause of extensive bullous impetigo?
Eczema underlying the bullous impetigo
A 3 yr old boy presents generally unwell with extensive, sever bacterial impetigo - what could be the underlying skin condition?
Eczema Herpeticum
How long does it usually take for impetigo to resolve without treatment?
2 - 3 weeks
What is erysipelas?
infection of the skin. It is a superficial form of cellulitis that most often involves the face.
Who is recurrent cellulitis most common in?
chronic lymphodema
What organisms causes cellultitis and erysipelas?
- streptococcus pyogenes
- staphylococcus aureus (in immunosuppressed and diabetes)
- Haemophilus influenza (children)
***Erysipelas almost always caused by group A beta haemolytic strep (Strep pyogenes)
What are the risk factors for cellultitis and erysipelas?
- defective skin barriers (e.g. fissuring of toes in athletes foot)
- venous disease ( ulcers)
- diabetes / immunosuppressed
- chronic lymphoedema
- previous cellulitis
What are the symptoms and signs of cellulitis?
- sudden onset of pain
- malaise, fevers, rigors precede the rash.
- unilateral warm, swollen, tender spreading erythema that is well demarcated , sometimes with blisters.
What are the differentials for cellultitis / erysipelas?
- DVT
- insect bite
- superficial thrombophlebitis
- varicose eczema
- vasculitis
- gout
- septic arthritis
What invx are done for cellulitis / erysipelas?
- blood culture (bacteraemia common in erysipelas)
- FBC (raise WCC)
- CRP (raised)
- U + Es
What is the treatment for cellultitis / erysipelas?
- Analgesia ( para or Ibu)
- Flucloxacillin and benzylepenicillin
- elevate affected limb
What are the complications of cellulitis?
- necrotising fasciitis
- gas gangrene
- sepsis
- endocarditis
Who is most commonly affected by erysipelas?
- infants
- elderly
What are the symptoms of erysipelas
Fever and rigors
- sharp raised border
- bright red, firm, swollen
- can be dimpled
- blistered
- purpura
- on face has a butterfly distribution
What areas are commonly affected by erysipelas?
Face (butterfly)
and Shins
What is Folliculitis?
- infection of hair follicle
- usually self limiting
- caused by shaving / waxing
How does folliculitis present?
- erythema
- pustules
What are the complications of deeper folliculitis infections?
- abscess
- can cause otalgia if in ear
