Bacterial, Fungal and Parasitic Infections Flashcards
Staph aureus is found in chains/clusters and is coagulase positive/negative
Clusters
Positive
What antibiotic should always be used to treat staph aureus?
Flucloxacillin
Which toxin produced by certain strains of staph aureus is important in skin infections?
Panton Valentin Leucocidin (PVL)
Is staph epidermidis a common disease causing organism?
No - it is a skin commensal
How are streptococcus species classified?
By haemolysis on blood agar
How are beta-haemolytic streptococci further classifed?
By antigenic structure on the surface (Group A or Group B)
Give some examples of organisms that are non-pathogenic skin commensals
Staph epidermidis
Corynebacterium sp.
Propionibacterium sp.
What are some bacterial skin infections caused by staph aureus?
Minor skin sepsis
Cellulitis
Infected eczema
Impetigo
What are some bacterial skin infections caused by strep pyogenes?
Infected eczema
Impetigo
Cellulitis
Necrotising fasciitis
How is a bacterial skin infection diagnosed?
Taking a swab of lesion or taking pus or tissue
How is necrotising fasciitis treated?
By surgery
Give the Latin and common name for a dermatophyte infection
Tinea
Ringworm
Give the Latin for ringworm on the scalp, body, hand, groin and foot
Tinea capitis - head Tinea corporis - body Tinea manuum - hand Tinea cruris - groin Tinea pedis - foot
How do dermatophytes enter the body?
The fungus enters through abraded or soggy skin before infecting keratinised tissues
Males are more commonly affected by ringworm than females. True/false?
True
What is the main source of tinea?
Other infected humans
Give the two most commonly causing organisms of tinea
Trichophyton rubrum
Trichophyton mentagraphytes
How can tinea be diagnosed?
Clinical appearance
Skin scrapings
Nail clippings
If there is a small area of skin infected with tinea, how is it treated?
Clotrimazole cream
How is an extensive infection of tinea treated?
Oral terbinafine
How does scabies present?
Intensely itchy rash affecting finger webs, wrists or genital areas
How is scabies treated?
Malathion lotion Benzyl benzoate (not in children)
Give examples of patients in dermatology who need single room isolation
Patients with group A strep
Patients with MRSA
Patients with scabies
