Skin infestations and infections Flashcards
What receptors does staphyloccus have?
receptors that allow it to bind to fibrin that is found in abundance on wound surfaces and in dermatitis
What are examples of conditions staphyloccus can form?
- Panton Valentine Leukocidin
- Ecthyma
- Impetigo
- Cellulitis
- Folliculitis
- Staphylococcal scalded skin syndrome (SSSS) - toxic shock syndrome
- Superinfects other dermatoses (e.g. atopic eczema, HSV, leg ulcers)
What are different types of folliculitis?
- Furunculosis
- Carbuncles
What are the difference virulence factors in steptoccous?
- Strepococcus pyogenes (β-haemolytic) attaches to epithelial surfaces via lipoteichoic acid portion of fimbriae
2, Has M protein (anti-phagocytic) & hyaluronic acid capsule - Produces erythrogenic exotoxins
- Produces streptolysins S and O
What presentations can streptoccocus show?
- Ecthyma
- Cellulitis
- Impetigo
- Erysipelas
- Scarlet fever
- Necrotizing fasciitis
- Superinfects other dermatoses (e.g. leg ulcers)
What is folliculitis?
Follicular erythema; sometimes pustular
Is folliculitis infectious?
infectious or non infectious
What type of folliculitis is associated with HIV?
Eosinophilic (non-infectious) folliculitis
When can there be recurrent episodes of folliculitis?
- from nasal carriage of Staphylococcus aureus
2. particularly strains expressing Panton-Valentine leukocidin (PVL)
What is the treatment of folliculitis?
- Antibiotics (usually flucloxacillin or erythromycin)
2. Incision and drainage is required for furunculosis
What is a furuncle?
deep follicular abscess
What is a carbuncle?
deep follicular abscess
with involvement with adjacent connected follicles
What can a carbuncle lead to?
more likely to lead to complications such as cellulitis and septicaemia
Why do some patients develop recurrent staphylococcal impetigo or recurrent furunculosis?
- Establishment as a part of the resident microbial flora
- Abundant in nasal flora - Immune deficiency
What immune deficiency can lead to some patients develop recurrent staphylococcal impetigo or recurrent furunculosis?
- Hypogammaglobulinaemia
- HyperIgE syndrome – deficiency
- Chronic granulomatous disease
- AIDS
- Diabetes Mellitus
What is panton valentine leukocidin (PVL)?
- β-pore-forming exotoxin
* Leukocyte destruction and tissue necrosis
What is the effect of panton valentine leukocidin?
Higher morbidity, mortality and transmissibility
How does PVL affect the skin?
- Recurrent and painful abscesses
- Folliculitis
- Cellulitis
- Often painful, more than 1 site, recurrent, present in contacts
What are the extracutaneous manifestations of PVL?
- Necrotising pneumonia
- Necrotising fasciitis
- Purpura fulminans
What are the 5Cs to getting PVL?
- Close Contact – e.g. hugging, contact sports
- Contaminated items , e.g. gym equipment, towels or razors.
- Crowding –crowded living conditions such as e.g. military accommodation, prisons and boarding schools.
- Cleanliness (of environment)
- Cuts and grazes – having a cut or graze will allow the bacteria to enter the body
How do you treat PVL?
- Consult local microbiologist / guidelines
- Antibiotics (often tetracycline)
- Decolonisation
- Treatment of close contacts
How do you deconlinse PVL?
- Chlorhexidine body wash for 7 days
2. Nasal application of mupirocin ointment 5 days)
What is pseudomonal folliculitis associated with?
hot tub use, swimming pools and depilatories, wet suit
When does pseudonomal follicultis appear?
1-3 days after exposure, as a diffuse truncal eruption
What happens during pseudonomal folliculitis?
- Follicular erythematous papule
* Rarely: abscesses, lymphangitis and fever
How do you treat pseudomonal folliculitis?
- Most cases self-limited – no treatment required.
* Severe or recurrent cases can be treated with oral ciprofloxacin