Skin and soft tissue infections Flashcards
How can skin and soft tissue infections be classified
By microbe
- bacteria
- virus
- fungi
By anatomy
- superficial
- deeper tissues
Basic description of s.aureus
Gram positive cocci. About 20-30% of us carry
Example of virulence factor for s. aureus
Panton Valentine Leukocidin (PVL) toxin - toxin which targets white cells. In epithelial cells they puncture membrane, also through polymorphs causing tissue necrosis
Disease caused by s.aureus
Pyogenic: Boils, carbuncles Wound infections Abscesses Impetigo Mastitis Pneumonia Endocarditis Bacteraemia Osteomyelitis
Toxin mediated:
Scalded skin syndrome
Toxic shock syndrome
Food poisoning
basic description of Strep. pyogenes
Gram positive chains. Beta haemolysis
virulence factor of strep. pyogenes
superantigens (effect is disproportionate to amount of antigen present, can bypass controls we have in place to stop overreaction) which is responsible for TSS
disease caused by strep. pyogenes
TSS
Basic description of strep. angionsus
gram positive chains
virulence factor for strep. anginosus
intermediysin (cytotoxin)
Disease for strep. anginosus
dental abscess
Basic description for anaerobes
gram positive rods (bacilli) e.g. clostridium sp
virulence factor for anaerobes
alpha toxin (lecithinase) - breaks down membranes
virulence factor for herpes simplex group
something which causes cell lysis (find out)
disease caused by herpes simplex group
genital herpes
neonatal herpes
herpes keratitis
Basic description of Candida albicans
Yeast cells, hypae (about 10x bigger than bacteria)
Virulence factor for candida albicans
phospholipase (breaks down cell membranes)
disease caused by candida albicans
candidiasis
What diseases would you get on the epidermis (most outer layer)
- impetigo
- angular cheilitis
- chicken pox
- shingles
What causes diseases on the epidermis
group A strep
staph aureus
V zoster (chicken pox/shingles)
What diseases would you get on the dermis
- erysipelas (superficial form of cellulitis)
- folliculitis (in hair follicles)
- boils (furuncle deep seated infection)
- carbuncles (deep seated infection with multiple heads)
difference between boil and carbuncle
boil = furuncle deep seated infection
carbuncle = deep seated infection with multiple heads
what infections can you get in subcutaneous fat
cellulitis
what infections can you get in fascia
necrotising fasciitis (need ab’s and surgery)
what infections can you get in the muscle
- myonecrosis
- gangrene
