Skin and soft tissue infections Flashcards
What us impetigo?
Superficial highly infectious skin infection
Multiple vesicular lesions on an erythematous base
What is highly suggestive of impetigo?
Golden crust
What are the causative organisms of impetigo?
Most common= staph aureus
Less commonly= strep pyogens
Where does impetigo occur?
Exposed areas e.g. face, extremities, scalp
What are the predisposing factors of impetigo?
Skin abrasions
Minor trauma or burns
Por hygiene
What is the treatment of impetigo?
Small areas= topical antibiotics
Large areas= topical treatment an oral antibiotics
What is erysipelas?
Infection of upper dermis
What are the clinical features of erysipelas?
Painful red area, no central clearing
Associated fever
Regional lymphadenopathy and lymphangitis
Distinct elevated borders
What is the commonest cause of erysipelas?
Strep pyogenes
Where is erysipelas most often seen?
Legs
Areas of existing lymphedema, venous stasis, obesity, paraparesis, diabetes mellitus
What is the treatment of erysipelas?
Combination of anti-staph and anti-strep antibiotics
IV antibiotics if severe
What is cellulitis?
Diffuse skin infection involving deep dermis and subcutaneous fat
What are the clinical features of cellulitis?
Spreading erythematous area with no distinct borders
Fever
Regional lymphadenopathy and lymphangitis
What are the most common causative organisms of cellulitis?
strep pyogenes
staph aureus
What are the predisposing factors for cellulitis?
DM
Tinea pedis
Lymphoedema
What is the treatment of cellulitis?
Combination of anti-staph and anti-strep antibiotics
IV antibiotics if severe
What are the hair associated infections?
Folliculitis
Furuncles
Carbuncles
What are the clinical features of folliculitis?
Circumscribed pustular infection of hair follicle
Up to 5mm in diameter
Small red papule
Central area of purulence that may rupture and drain
Where is folliculitis found?
Head
Back
Buttocks and extremities
What is the most common causative organisation of folliculitis?
Staph aureus
What is the treatment of folliculitis?
None or topical antibiotics
What are furuncles commonly referred to as?
Boils
What are the clinical features of furuncles?
Single hair follicle associated with inflammatory nodule
Extending to dermis and subcutaneous tissue
Where do furuncles occur?
Moist, hairy, friction prone areas
What is the most common causative organism of furuncles?
Staph aureus
What are the risk factors for furuncles?
Obesity
DM
CKD
What is the treatment of furuncles?
None
Topical antibiotics
If not improving, oral antibiotics
When do carbuncles occur?
Infection extends to involve multiple follicles
Where do carbuncles often occur?
Back of neck, posterior trunk or thigh
What are the clinical features of carbuncles?
Multiseptated abscesses
Purulent material may be expressed
What is the treatment of carbuncles?
Often require hospital admission, surgery and IV antibiotics
What are the predisposing factors for necrotising fasciitis?
DM
Surgery, trauma
Peripheral vascular disease
Skin popping
What are the types of necrotising fasciitis?
Type I- missed infection, typically strep, staph or enterococci
Type II- mono microbial, associated with strep pyogenes