CELLULITIS AND NECROTIZING FASCIITIS Flashcards
Acute spreading infection involves the deeper dermis and
superficial subcutaneous tissues. ?
Cellulitis
most common organisms?
- Group A streptococci
- S. aureus : commonly causes cellulitis- penetrating trauma.
- Haemophilus influenzae: periorbital cellulitis in children
commonly causes cellulitis- penetrating trauma. ?
• S. aureus
Cause periorbital cellulitis in children ?
Haemophilus influenzae
Cellulitis Risk factors?
- Obesity
- preexisting skin infections-
ulceration, or eczema,
• CA-MRSA
-More sensitive to antibiotics
-Can lead to sever skin and soft tissue infection or septic shock
Diagnosis of Cellulitis?
- Clinical diagnosis Symptoms and Signs
- Laboratory investigation :
-High WBCs, blood culture rarely needed
-Observe for progression to sever infection(increased in size with systemic
manifestation :fever, leukocytosis)
Treatment of Cellulitis?
Vancomycin
• It is a rare deep skin and subcutaneous tissues infection ?
Necrotizing fasciitis(Flesh-eating disease)
an uncommon but rapidly progressive and life
-threatening infection of the deep dermis, adipose tissue and
subcutaneous fascia.?
Necrotising fasciitis (NF)
monomicrobial (Type II) or (polymicrobial Type I) infection ?
Necrotizing fasciitis(Flesh-eating disease)
Most common in the arms, legs, and abdominal wall and is fatal ?
Necrotizing fasciitis(Flesh-eating disease)
Risk factors
Of Necrotizing fasciitis(Flesh-eating disease)
Immune-suppression • Chronic diseases: ( diabetes, liver and kidney diseases, malignancy • Trauma:(laceration, cut, abrasion, contusion, burn, bite, subcutaneous
injection, operative incision) • Recent viral infection rash (chickenpox) • Steroids • Alcoholism • Malnutrition • Idiopathic
Most common organisms of Necrotizing fasciitis(Flesh-eating disease)
?
- Monomicrobial
• Group A streptococcus (Streptococcus pyogenes)
• Staphylococcus aureus or CA-MRSA
2.Polymicrobial
• Caused by aerobic and anaerobic bacteria
• Gram-negative bacteria (synergy).
Classification of necrotizing fasciitis
? Very imp
Type 1: polymicrobial
Type2: monomicrobial
Type3: marine vibrio vulnifius
Type4: MRSA
Pathophysiology of necrotizing fasciitis
?
Destruction of skin and muscle by releasing toxins • Streptococcal pyrogenic exotoxin • Superantigen • Non-specific activation of T-cells • Overproduction of cytokines • Severe systemic illness (Toxic shock syndrome)
Signs and symptoms of necrotizing fasciitis
?
• Rapid progression of sever pain with fever , chills (typical) • Swelling , redness, hotness, blister, gas formation, gangrene and necrosis • Blisters with subsequent necrosis , necrotic eschars • Diarrhea and vomiting (very ill) • Shock organ failure • Mortality as high as 73 % if untreated
Diagnosis of Necrotising fasciitis ?
• A delay in diagnosis is associated with a grave prognosis and
increased mortality • Clinical-history and examination • Blood tests • CBC-WBC , differential , ESR • BUN (blood urea nitrogen) • Surgery debridement- amputation • Radiographic studies • X-rays : subcutaneous gases • Doppler CT or MRI • Microbiology • Culture &Gram’s stain • ( blood, tissue, pus aspirate) • Susceptibility tests
NF should be suspected in the following scenarios: ?
If the level of pain and tenderness, or systemic upset, is out of proportion to
the physical signs • Dusky-violaceous areas along with erythema • Crepitus • Over a short period of time blisters develop, the affected area becomes
necrotic, and the patient very toxic
Treatment of NF?
• If clinically suspected patient needs to be hospitalized OR require admission
to ICU • Start intravenous antibiotics immediately • Antibiotic selection based on bacteria suspected • broad spectrum antibiotic combinations against: • methicillin-resistant Staphylococcus aureus (MRSA)
Antibiotics combinations
