Skin and soft tissue infections Flashcards
What is the most distinguishing clinical feature of Impetigo?
Golden crust - the vesicular lesions that form with the infection rupture and ooze substances that form golden crust
Predisposing factors for impetigo?
- Skin abrasions
- Minor trauma
- Burns
- Poor hygiene
- Insect bites
- Chickenpox
- Eczema
- Atopic dermatitis
Treatment of impetigo
Small areas can be treated with topical antibiotics alone
Large areas need topical treatment and oral antibiotics (ex flucloxacillin)
Most common causative organism in Erysipelas?
Strep pyogenes
Describe how an Erysipelas infection presents
- Infection of the upper dermis - typically has distinct elevated borders i.e you can feel where it starts and ends
- Painful, red area
- Associated fever and regional lymphadenopathy and lymphangitis
- 70-80% of cases involves the lower limbs, 5-20% affect the face
How would you treat Erysipelas?
A combination of anti-staphylococcal and anti-streptococcal antibiotics i.e flucloxacillin, clarithromycin or co-amoxiclav etc
In extensive disease, admission for intravenous antibiotics and rest
How would you treat Cellulitis?
1st line = flucloxacillin, clarithryomycin, co-amoxiclav
In extensive disease, admission for intravenous antibiotics and rest
What is cellulitis?
Diffuse infection of the skin and the soft tissues underneath (deep dermis and subcutaneous fat)
What are the most likely causative organisms for cellulitis? (3)
Staph aureus Strep pyogenes Strep dysgalactiae MRSA also can be a cause
How does cellulitis present?
- Presents as a spreading erythematous area with no distinct borders
- Fever is common
- Regional lymphadenopathy and lymphangitis
What are some common predisposing factors of cellulitis?
- DM
- Tinea pedis ‘athletes’ foot’
- Lymphoedema
What is folliculitis?
- An infection of one hair follicle that has not extended beyond
- Small red papules with purulent centre
- Benign
- Typically found on head, back, buttocks and extremities
What is furunculosis?
- This is otherwise known as a boil
- The infection has breached the hair follicle to extend to the surrounding areas
- Usually affects moist, hairy, friction-prone areas of body (face, axilla, neck, buttocks)
- May spontaneously drain purulent material
What are carbuncles?
- Known as an abscess of the skin – involves numerous hair follicles
- Often located back of neck, posterior trunk or thigh
- Purulent material may be expressed from multiple sites + systemic features
- Can require hospital admission, surgical drainage + IV antibiotics
What is the most common organism causing folliculitis and furunculosis?
Staph aureus
Is there any treatment for folliculitis or furunculosis?
No
Treatment of Carbuncles
Often require admission to hospital, surgery and IV antibiotics
What is necrotising faciitis?
One of the infectious diseases emergencies affecting the fascia (deepest part of the skin)
What can predispose you to necrotising fasciitis?
- DM
- Surgery
- Trauma
- Peripheral vascular disease
- Skin popping - injecting illicit drugs into the dermis or subcutaneous tissue with the goal of achieving slower absorption, decreased risk of overdose, or easier administration than with IV drug administration.
What is type 1 necrotising fasciitis? Give examples
- Type I refers to a mixed aerobic and anaerobic infection i.e. diabetic foot infection, Fournier’s gangrene
- Typical organisms include:-
- Streptococci
- Staphylococci
- Enterococci
- Gram negative bacilli
- Clostridium