1. 1396/02/21

2. Bacterial skin and soft tissue infection
Dr Nasser Mostafavi
Departement of Pediatric Infectious Disease
Isfahan University of Medical Sciences
1396/02/21

3. Skin and soft tissue infection
Non necrotizing:
Nonpurulent:
Cellulitis
Erysipelas
Purulent:
Impetigo, echtyma
Folliculitis, furuncle, carbuncles, skin abscesses
Necrotizing :
Necrotizing fasciitis
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4. Cellulitis
Infection of the deep dermis and subcutaneous fat: indistinct margins
Break to the skin ( trauma, stasis, eczema)
Streptococcus pyogene, S. aureus, Rarely gram-negative aerobic bacilli
Indolent course of edema, warmth, erythema, and tenderness of the skin
Commonly fever, and regional adenopathy
Sometimes lymphangitis, suppuration
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5. Cellulitis of the leg
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6. Cellulitis of foot
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7. Treatment of cellulitis
Mild infection: Oral cephalexin or clindamycin for 5-10 days
Moderate infections: IV cloxacillin /clindamycin
Fever
Lymphadenopathy
Rapid progression
Progression of symptoms hours of oral therapy
Persistence of symptoms hours of oral therapy
Severe infection (Systemic toxicity) : IV cloxacillin/ clindamycin + Vancomycin
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8. Persistence of symptoms after 48-72 h.
Underlying infection( OM, abscess, ..) : imaging
Resistant organism: Culture, coverage for resistant organisms and gram-negative bacilli
Slow response to therapy: Extension of the duration (up to 14 days)
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9. Erysipelas
Infection of the upper dermis and superficial lymphatics: sharply defined, slightly elevated border
Skin abrasion
Group A streptococcus, sometimes H.inf type b, and S. pneumonia
Mostly in face, ear and lower extremities
Usually abrupt onset+ high fever and rapid progress
IV penicillin+ clindamycin until improvement and culture results( blood, margin) then oral penicillin, amoxicillin, cephalexin, or clindamycin for 5-10 days
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10. Erysipelas of the lower leg
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11. Erysipelas of the face
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12. Specific forms of cellulitis
Neonatal
Buccal( facial) cellulitis
Periorbital cellulitis
Perianal cellulitis:
Lymphangitis
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13. Neonatal Cellulitis  
Usually requires hospitalization except for the mildest of cases
Coverage for GBS, MRSA, and BH streptococci, enteric gram negatives
Sepsis work up including LP
Vancomycin plus either cefotaxime or gentamicin for 7-10 d
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14. Neonatal cellulitis
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15. Perianal (vaginal) dermatitis
Marked well demarcated perirectal erythema with swelling, pruritus, and tenderness, no fever, no progressive disease
Group A beta hemolytic streptococcus
Oral penicillins +/- topical mupirocin
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16. Perianal dermatitis
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17. Buccal( facial) cellulitis
Violaceous hue of the cellulitic area in the face of infants with no clear skin abrasion
Nearly always hematogenous seeding by H. influenzae type b
Meningitis in 15-20%
Treatment: LP
Ceftriaxone + clindamycin/ vancomycin
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18. Facial cellulitis
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19. Facial cellulitis
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20. Preseptal cellulitis
Infection of the eyelids anterior to the orbital septum
Erythema, tenderness and edema of the eyelids
No restricted or painful ocular motility, decreased vision, and proptosis
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21. Preseptal cellulitis
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22. Preseptal cellulitis
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23. Pre-septal cellulitis
Types:
Posttraumatic: S. aureus, S. pyogenes
Nontraumatic: S. pneumoniae, H. influ type b( 2-3% meningitis)
Treatment:
Posttraumatic: clindamycin
Nontraumatic:
LP in systemic toxicity, fever, and extremely young children
Clindamycin+ ceftriaxone
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24. Impetigo
Superficial bacterial infection that progress from papules to vesicles, pustules, and crusts
Nonbullous : ( Staph. aureus+ GABHS)
Rapidly progress from vesicle to pustule
Few to 10 mm size
Margin of erythema
Honey colored crust
Sometimes adenopathy and spread to exposed area
Bullous: (Staph. aureus only)
Small vesicle that progress to flaccid painless bulla> 1 cm
Erythematous moist base after rupture
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25. Non bullous impetigo
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26. Multiple non bullous impetigo
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27. Bullous impetigo
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28. Bullous impetigo
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29. Treatment of impetigo
Localized non-bullous: Topical mupirocin/ tetracyclin (10-14 d)
Bullous/ widespread non-bullous : Oral cephalexine, clindamycin, co-trimoxazol
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30. Ecthyma An ulcer with elevated margins( till 4 cm)
A vesicle or pustule that erodes the dermis
The ulcer obscured by dry, adherent crust
Autoinoculation
Mostly on the legs
GABHS
Penicillin+ warm compresses
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31. Ecthyma
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33. Folliculitis
Superficial infection of the hair follicles with purulent material
Small, dome-shaped pustules with an erythematous base
Scalp, buttocks, and extremities
Poor hygiene, maceration, and shaving of the legs
Most often S. aureus
Treatment:
Mild cases: topical mupirocin/tetracyclin/clindamycin BID
Moderate to severe cases:
culture
Oral cephalexin/ clindamycin/ co-trimoxazol
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34. Folliculitis
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35. Folliculitis
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36. Pseudomonal folliculitis (hot tub folliculitis)
8-48 hr. after exposure to poorly chlorinated hot tubs and swimming pools
Most dense in areas covered by a bathing suit
Pruritic papules and pustules or deep nodules
Occasionally fever, malaise, lymphadenopathy
Usually resolves spontaneously in 1-2 wk
Often post-inflammatory hyperpigmentation
Treatment : ciprofloxacin if fever or constitutional symptoms
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37. Hot tube folliculitis
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38. Hot tube folliculitis
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39. Furuncle (or "boil“) Small abscess of the hair follicle
Deep-seated, tender, erythematous, peri- follicular nodule
Initially indurated, then necrosis and suppuration
Face, neck, axillae, buttocks, and groin
Usually follow folliculitis
Usually no constitutional symptoms
Usually S.aureus
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40. Furuncle
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41. Furuncle
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42. Furuncle
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43. Carbuncle
Infection of a group of contiguous follicles, with multiple drainage points
Sometimes fever
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44. Carbuncle
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45. Carbuncle
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46. Treatment of furuncle and carbuncle
Regular bathing with antimicrobial soaps (chlorhexidine)
Loose-fitting clothing
Frequent hot, moist compress for drainage
Incision of large lesions
Oral antibiotics( clindamycin, cephalexin, co- trimoxazole, cloxacillin, …) for 5-7 days in most cases
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47. Necrotizing fasciitis
Progressive destruction of the muscle fascia
Acute fever with erythema, edema and exquisitely tender area
Pain out of proportion to exam findings
After hr.: bulla , ecchymosis, crepitus, anesthesia, and necrosis of the skin
Sometimes shock, organ failure, and death within houres
Risk factors: DM, immunosuppression, skin abrasion especially abdomenal, GU, GI, perineal surgery
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48. Necrotizing fasciitis
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49. Necrotizing fasciitis
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50. Microbiology of necrotizing fasciitis
Usually polymicrobial: S. aureus, streptococci, anaerobes, enteric gram negatives( Klebsiella, E. coli)
Crepitans in Clostridium spp. or Gram- negative bacilli
The rest and the most fulminant infections: GABHS
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51. Diagnosis
Surgical exploration: as soon as the suspicion, grey necrotic tissues
Frozen-section biopsy: ↓ time to diagnosis, establish margins
CT and MRI: in low suspicion, delineating the extent
Gram staining of tissue: S. pyogenes or polymicrobial
Culture of tissue
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52. Treatment Early supportive care Repeated debridement within 24-36 hr.
Meticulous daily wound care
Parenteral antibiotic:
Empiric: vancomycin+ piperacillin-tazobactam/ ceftriaxone with metronidazole
In documented GAS: Penicillin with clindamycin
Hyperbaric oxygen therapy: helpful
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53. 1396/02/21