Skin and soft tissue infections Flashcards
Layers
epidermis dermis subcut fat fascia muscle
Risks
diabetes immunosuppression renal failure Milroy's disease- lymphedema in legs predisposing skin conitions eg atopic dermatitis
Impetigo
gold crusty lesions staph A common strep pyogenes less common kids 2-5 yrs highly infectious face, extremities, scalp
Impetigo treatment
topical antibs small areas
large need topical and oral antibs
Erysipelas
inf upper dermis painful red area fever lymphademopathy and lymphangitis distinct elevated borders strep pyogenes lower limbs most common and some face
Erysipelas treatment
oral or IM penicillin
5 days
cephalosporin if penicillin allergy
Cellulitis
deep dermis and subcut fat spreading erythematous area w no distinct borders strep pyogenes and staph a fever lympahdenopathy and lympangitis
Cellulitis risk
diabetes
tinea pedis
lymphoema
Cellulitis treat
anti-staph and anti-strep antibs
dicloxacillin
amoxicillin
cephalezin
Folliculitis
circumscribed, pustular infection of hair follicle
small red paupules
head, back, buttocks and extremities
staph a
Furunculosis
furuncles commonly referred as boils single hair collice assoc inflam nodules dermis and subcut tissues face, axilla, neck, buttocks staph a risks w obestiy, DM, CKD, corticosteroids
Carbuncle
when infection extends to invulve multople furuncles
back neck, posteror trunk or thigh
multi septated absecess
Furunculosis treat
hot copress
hot bath
no antibs unless not improving give oral
Carbuncle treat
admission to hosp
surgery
IV antibs- rifampicin and clindamycin
Necrotising fasciitis
emergency
risks- diabetes, surgery, trauma, vasuclar disease
Necrotising fasciitis type 1
mixed aerobic and anaerobic infection
diabetes foot
fourniers gangrene
strep, staph,enterococci, gram neg bacili, clostridium
Necrotising fasciitis type 2
monomicrobial nromally strep pyogenes rapid onset erythema- oedema- pain haemorrhagic bullae, skin necrosis fever, hypotension, tachy, delirium, multiorgan failure need surgical review and anaethesia broad spectrum antibs- flucclox,gent
Pyomyositis
purulent infection deep within striated myscle, often manifesting abscess
secondary to seeding into damaged muscle
thigh, calf, arms, glutes, chest wall, psoas
fever, pain, woody induration affected muscle
commonly staph A
CT/MRI
Pyomyositis risks
diabetes HIV/immunosupp IVDU rheumatological disease malignancy liver cirrhosis
Pyomyositis treat
drainage
antibs
Septic bursitis
commonly patellar and olecranon infection bursa swelling red and warm commonly staph a fever and pain on movement diagnose by aspiration of fluid
Septic bursitis risks
rheumatoid arthirits alcoholism diabetes IVDU immunosupp renal insufficiency
Infective tenosynovitis
infection of synovial sheets surrounding tendons
penetrating trauma commonly before
staph a or strep
erythematous fisiform swelling of finger
held in semi flexed position
tender over tendon sheet and pain w extension fingers
Infective tenosynovitis treat
empiric antibs
hand surgeon review
Toxin mediated syndromes
often due to superantigens group of pyrogenic exotoxins activate T cell pool themselves massive busrst cytokine release leads to endothelial leak, haemodynamic shock and multi orgam failure and deaths mostly staph A or strep pyogenes
Toxic shock syndrome staph
fever
hypotension
diffuse macular rash
involve other organs- liver, blood, renal, GI, CNS
isolation of staph a from mucosal or nromally sterile sites
Toxic shock syndrome strep
aoss w presence of strep in deep seated infections like necortising fasciitis
mortality high
urgent surgical debridement of infected tissues
Toxic shock syndrome treatment
remove oddending agent eg tampon IV fluids inotropes antibs IV immunoglobulins
Intravenous catheter associated infections
start w local inflam progressing to cellulitis and tissue necrosis
associated bacteraemia (bacteria in blood)
common staph A - MSSA and MRSA
commonly forms biofilm which spills into bloodstream
blood cultures
Intravenous catheter associated infections management
remove cannula
express pus from thrombophlebitis
antibs 14 days
echo
Intravenous catheter associated infections prevention
dont leave unused cannula change every 72 hrs careful continuous infuse more than 24hrs monitor thrombophlebitis aseptic techniques
Surgical site infections causes
staph a inclu MSSA and MRSA coagulase neg staph enterococcus e coli pseudomonas aeruginosa enterobacter strep fungi anaerobes
Surgical site infections risk
diabetes smoking obese malnutrition steroid use colonisation shaving site improper preop skin prep break sterile technique inadequate theatre ventillation periop hypoxia
Surgical site infections diagnosis
send pus/infected tissue for cultures
avoid superficial swabs aim for deep structures
consider an unlikely pathogen as a cause if obtained from sterile site
Surgical site infections treat
antibs to target likely organisms
