Lecture 16: Skin/Soft Tissue Infections Flashcards
What are the most common Skin/Soft Tissue Infections?
- Impetigo
- Erysipelas
- Cellulitis
- Necrotizing Faciitis
- Diabetic Foot Infections
MOST COMMONLY caused by b-hemolytic strep & Staph aureus
What are some of the mechanisms of defense for S/STi?
- Skin [physical barrier]
- Low pH [~5.6]
- Dry environments
Alteration to any of these will cause a skin infection
What are the common skin flora?
- Corynebacterium Diphtheriae
- Staph Epidermidis
- Streptococci [Group]
- Cutibacterium
What are some of the important risk factors asscoiated with S/STi?
- Immune Status
- Geographic Location
- Lifestyle
- Traveling
- Reacent trauma or surgery
- PHM
- etc
Which of the following can predispose a patient for a S/STi?
A] Decreased skin perfusion
B] Availability of bacterial nurtients
C] Damage to the skin
D] All of the above
- D] All of the above
What is the Impetigo?
- Purulent Superficial Infection involving the epidermis that have mulitple pustules rupture on the FACE & EXTREMITIES
HONEY colored look
What are some of the symptoms of Impetigo?
- Maculopapular lesions that rupture leaving icthy or painful honey colored crust
- VERY INFECTIOUS
What is the pathogensis of Impetigo?
- Organisms directly invade skin [primary] OR superficially [epidermis] during a trauma [secondary]
What are some of the risk factors for Impetigo?
- Chlidren [Day Care Settings]
- Skin Trauma
- Hot/Humid Climates
- Poor Hyigene
- Crowding
- Malutrition
- DM
Can basically spread very easily
What are some of the common bacteria that cause Impetigo?
- Staph Aureus
- Sterp Pyogenes
What is the treatment for Impetigo?
- Cephelaxin: Adults - 250-500mg PO QID & Kid 25-50mg/kg/d PO in 3-4 divided doses
True or False: Impetigo most commonly occurs in adults and is not contagious?
- FALSE
What is Cellulitis?
- Acute spreading infection involving the skin
- Mostly in the lower extremities
What are some of the symptoms of Cellulitis?
- Redness, Tenderness, Warmth, Sweeling with a poorly defined border
- Possibly fever, malaise, lymphadoenopathy, lymphangitis…
What is the pathogensis of Cellulitis?
- Organisms into the skin during trauma, wounds, Athletes Foot, cracked skin, injections, ulcers surgery…
Basically anything that alters the integrity of the skin
What are some of the risk factors for Cellulitis?
- DM
- IV drug usage
- Obesity
- Lymphedema
- Immunocompromised
What are some of the important characterisitcs of CA-MRSA?
- Close Contact [immates, injections, contact sports, children, tattoos…]
- SCCmec type IV
- Panton-Valentine Leukocidin [PVL] - causes necrosis & abcess
- Cellulitis AND Abscess
What is the empiric treatment for Cellulitis in Mild/Moderate Patients
PO: Dicloxacillin OR Cephalexin
CA-MRSA: SMX/TMP OR Clindamycin OR Linezoild
same in kids
MRSA should be suspected in patients whose cellulitis is assoicated with trauma, MRSA elsewhere, nasal PCR, Injections, purulent or SIRS
What is the empiric treatment for Cellulitis in Moderate/Severe Patients?
- IV: Nafcillin OR Cefazolin
- CA-MRSA: Vancomycin OR Linezolid
MRSA should be suspected in patients whose cellulitis is assoicated with trauma, MRSA elsewhere, nasal PCR, Injections, purulent or SIRS
For Cellulitis, what does the empiric treatment depend on?
- Purulent = BOTH Staph Aureus and Group Strep
- Non-Purulent = Group Strep and MSSA
What is the Directed Treatment for Cellulitis?
S. Pyogenes? MRSA? Gram (-)?
- S.Pyogenes: Penicillin
- MRSA: Vancomycin, SMX/TMP, Clindamycin, Doxycycline
- Gram (-): 3rd Gen Cephalo
5-7 Day treatment
What is Erysipelas?
- Cellulitis Variant from b-hemolytic strep that has sharp demarcated boarders
- PEAU D’ ORANGE on FACE
Which of the following best describes cellulitis?
A] Also called Peua d’ orange
B] Most often involves the face
C] Has Poorly defined margins
D] Involves only the upper dermis
- C] Has poorly defined margins
What is Necrotizing Faciitis?
- Rare skin infection that has progessive destrution of fascia, subq fat and mucsle
- On lower extremities, abdomen, or genitals
What are some of the symptoms of Necrotizing Fasciitis?
- Intense pain, wooden-hard skin, gangrene and system toxicity
What is the pathogensis of Necrotizing fasciitis?
- Same as Cellulitis BUT has toxin producing orgainsm
What are some of the bacteria that can causes Necrtoizing Fasciitis?
- Extremities: S. Pyogenes [toxin producing] & S. Aureus [CA-MRSA]
What is the empiric treatment for Encrotizing fasciitis?
- Vanomycin [MRSA]
- Pip/Tazo OR meropenem [GNR + Anaerobes]
- Clindamycin [Toxin Production]
Could also do Pip/Tazo OR Meropenem + Linezoild [MRSA + Toxin Production]
Which of the following should be started if there is a concern for a Necrotizing Skin Infection?
A] Clindamycin
B] Ceftriaxone
C] Vancomycin
D] Pip/Tazo
- A] Clindamycin
- C] Vancomycin
- D] Pip/Tazo
What are Diabetic Foot Infections?
- Infected foot ulcers, abscesses, cellulitis of the foot
- Infalmmatory process involving a foot wound
Want to look at the Ankle Brachial Index, Cultures Labs [WBC…]
What are the symptoms of Diabetic Foot Infections?
- At least 2 of the following:
- Redness, Warmth, Swelling, Tenderness, Pain, Purulent Discharge
May also have; fever, tachycardia, leukocytosis…
What is the Pathogenesis of Diabetis Foot Infections?
- Cause by neuropathy, angiopathy with ischemia, dry skin, decreased wound healing….
- Patient has ulcer -> dont know b/c neuropathy -> DFI
What is the Mild Wound Classifiation for Diabetis Foot Infection?
- S&S: Redness > 0.5 but < 2cm
- Systemic?: NO
- Bone?: NO
What is the Moderate Wound Classification for Diabetic Foot Infections?
- S&S: Redness > 2cm; deeper wound
- Systemic?: NO
- Bone?: NO
What is the Severe Wound Classification of Diabetic Foot Infections?
- S&S: Redness ANY size
- Systemic?: SIRS [2 of 4]
- Bone?: Potentially
SIRS: Temp > 38; HR > 90bpm; RR > 20; WBC > 12K or <4k
What are some of the MDR organism Risk Factors for Diabetic Foot Infections?
- MRSA: Hx of MRSA, MRSA > 30-50%, Hospitalization in last 30 days
- Pseudo: Soaking Feet, Wetness
What are some of the treatment options for Mild Diabetic Foot Infections?
NO Factors? B-lactam Allergy? Recent Antibios? MRSA?
- NO Factors: Cephalexin, Dicloxacillin, Augmentin
- B-lactam Allergy: Clindamycin, SMX/TMP, Doxycycline
- Recent Antibios: Augmentin, SMX/TMP
- MRSA: SMX/TMP, clindamycin, doxycycline, linezoild
NO Factors & B-lactam Allergy: Staph, Strep
Recent Antibios: GNR + GPCs
MRSA: MRSA
What are some of the treatment options fro Moderate Diabetic Foot Infections/
NO Factors? Recent Antibios? Warm Ulcers? MRSA? Ischemic Necro?
- No Factors: IV Unasyn, Cefazolin
- Recent Antibios: Ceftriaxone
- Warm Ulcers: IV Zosyn, Mero/Imip
- MRSA: + IV Vancomycin, Daptomycin, Linezolid
- Ischemic Necro: Zosyn, Carbas OR Ceftriaxone/Cefepime + Metro
NO Factors: b-hemo Strep and/or staph
Recent Antibios: Enterbacterales
Warm Ulcers: GNR, Pseudo
MRSA: MRSA
Ischemic Necro: GPC + GMR + Anaerobes
What are some of the treatment options for Severe Diabetic Foot Infections?
SIRS?
- SIRS: Vancomycin + [Zosyn, Mero, Ceftazidime/cefepime] + Metro
SIRS: B-hemo Strep and/or Staph [MSSA & MRSA], Enterbacterlaes, Pseudo
