Soft Tissue Infections Flashcards
what causes impetigo?
> STAPH AUREUS
> strep pyogens
what is impetigo?
a highly infective superficial skin infection that has multiple vascular lesions on erythematous base
how does impetigo present?
> golden crust
on exposed body part (face, scalp, extremities)
children 2-5
what are some predisposing factors to impetigo?
> abrasions > burns > eczema > poor hygiene > insect bites > chicken pox > atopic dermatitis
how is impetigo treated?
> small areas with topical antibiotics
> large areas with topical and oral antibiotics
what cause erysipelas?
strep. pyogens
what is erysipelas?
infection of the epidermis
how does erysipelas present?
> painful red area with a distinct border
fever
regional lymphadenopathy
what risk factors are there for erysipelas?
> DM
obesity
paraparesis
venous stasis
how is erysipelas treated?
combination of anti-staphylococcal and antistreptococcal antibiotics (extensive need rest and IV antibiotics)
what causes cellulitis?
> strep pyogens
> staph aureus
what is cellulitis?
diffuse skin infection involving the deep dermis and subcutaneous fat
how does cellulitis present?
> fever
spreading erythematous area with no distinct border
regional lymphadenopathy
how is cellulitis treated?
combination of anti-staphylococcal and anti-streptococcal antibiotics
what are the predisposing factors for cellulitis?
> DM
tinea pedis
Lymphedema
what are the predisposing factors for necrotising fasciitis?
> peripheral vascular disease > skin popping > trauma > surgery > DM
what causes type 1 necrotising fasciitis?
mixture of aerobes and anaerobes >enterococci > staphylococci > -ve bacilli > streptococci > clostridium
what causes type 2 necrotising fasciitis?
> strep pyogens
how does necrotising fasciitis present?
> rapid onset > haemorrhagic bullae > skin necrosis > crepitus > anaesthesia at site
what are the systemic features of necrotising fasciitis?
>fever > hypotension > delirium > multi-organ failure > tachycardia
what is the presentation of sequential development in necrotising fasciitis?
> severe pain
extensive oedema
erythema
what is the management of necrotising fasciitis?
> surgical review
> broad spectrum antibiotics (flucloxacillin, gentamicin, clindamycin)
what is polymyositis?
infection of deep striated muscle
what causes polymyositis?
staph aureus
what are the predisposing factors for polymyositis?
> liver cirrhosis > malignancy > DM > IV drug abuse > immunocompromised > rheumatological disease
what investigations could you carry out for polymyositis?
> CT
> MRI
how does polymyositis present?
> fever
pain
woody induration of the affected muscle
where does polymyositis present?
> arm > thigh > psoas muscle > calf > gluteal region > chest wall
how is polymyositis treated?
antibiotics and drainage
what is infectious tenosynovitis?
infection of the synovial sheets surrounding the tendons
what causes infectious tenosynovitis?
> penetrating trauma
STAPH AREUS
STREPTOCOCCI
chronic- fungi and microbacteria
how does infectious synovitis present?
> tenderness
finger in semi-flexed position (extension painful)
erythematous pusiform swelling
how is infectious synovitis treated?
> empirical antibiotics
what is folliculitis?
pustular infection of hair follicle
what causes folliculitis?
staph aureus
how does folliculitis present?
> small red papules
what are furunculosis?
single hair follicle associated inflammatory nodules, extended into the dermis and subcutaneous tissue
what are the risk factors for furunculosis?
> obesity > CKD > DM > atopic dermatitis > corticosteroid use
where does furunculosis present?
moist hairy friction prone areas
what cause furunculosis?
staph. aureus
what is a carbuncle?
infection involving multiple follicles ( a multi septated abscess)
how does a carbuncle present?
high temperature
how is a carbuncle treated?
surgery and IV antibiotics
what are some predisposing factors to septic bursitis?
> rheumatoid arthritis > alcoholism > DM > IV drug abuse > immunosuppression > renal insufficiency
how does septic bursitis present?
> peri-bursal cellulitis > warmth > swelling > fever > pain on movement
how is septic bursitis diagnosed?
aspiration of fluid
what causes septic bursitis caused?
staph aureus
what causes toxin mediated syndromes?
super antigens of pyrogenic exotoxins activated the immune system by attaching directly to the T cell receptors causing a massive cytokine release
how does staphylococcal TSS present?
> fever
hypotension
diffuse macular rash
3 organ involvement (GI, renal, liver, MSK, CNS)
how is streptococcal Toxin shock syndrome treated?
urgent surgical debridement of infected tissue
how is toxic shock syndrome managed?
> IV fluids > removing the offending agent > inotropes > antibiotics > IV immunoglobulins
how does staphylococcal scalded skin syndrome present?
> widespread bullae
> skin exfoliation
what causes panton-valentine leucocidin toxin?
gamma haemoglobin
what are the risk factors for IV catheter infections?
> cannula in situ for >72 hours
neurological problems
cannula in lower limb
how are IV catheter infections prevented?
> do not leave in an unused catheter
change cannula every 72 hours
monitor for thrombophlebitis
use aseptic technique
what are the risk factors for surgical site infections?
> diabetes > obesity > smoking > malnutrition > concurrent steroid use > staph aureus colonisation > procedural factors
describe class 1 surgical site infection
clean wound
resp/GI /uro/genital systems not entered
describe a class 2 surgical site infection
clean contaminated wound
describe a class 3 surgical site infection
contaminated wound
describe a class 4 surgical site infection
infected wound
