1396/02/21

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

Skin and soft tissue infection Non necrotizing: Nonpurulent: Cellulitis Erysipelas Purulent: Impetigo, echtyma Folliculitis, furuncle, carbuncles, skin abscesses Necrotizing : Necrotizing fasciitis 1396/02/21

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 1396/02/21

Cellulitis of the leg 1396/02/21

Cellulitis of foot 1396/02/21

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 24-48 hours of oral therapy Persistence of symptoms 48-72 hours of oral therapy Severe infection (Systemic toxicity) : IV cloxacillin/ clindamycin + Vancomycin 1396/02/21

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) 1396/02/21

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 1396/02/21

Erysipelas of the lower leg 1396/02/21

Erysipelas of the face 1396/02/21

Specific forms of cellulitis Neonatal Buccal( facial) cellulitis Periorbital cellulitis Perianal cellulitis: Lymphangitis 1396/02/21

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 1396/02/21

Neonatal cellulitis 1396/02/21

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 1396/02/21

Perianal dermatitis 1396/02/21

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 1396/02/21

Facial cellulitis 1396/02/21

Facial cellulitis 1396/02/21

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 1396/02/21

Preseptal cellulitis 1396/02/21

Preseptal cellulitis 1396/02/21

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 1396/02/21

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 1396/02/21

Non bullous impetigo 1396/02/21

Multiple non bullous impetigo 1396/02/21

Bullous impetigo 1396/02/21

Bullous impetigo 1396/02/21

Treatment of impetigo Localized non-bullous: Topical mupirocin/ tetracyclin (10-14 d) Bullous/ widespread non-bullous : Oral cephalexine, clindamycin, co-trimoxazol 1396/02/21

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 1396/02/21

Ecthyma 1396/02/21

1396/02/21

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 1396/02/21

Folliculitis 1396/02/21

Folliculitis 1396/02/21

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 1396/02/21

Hot tube folliculitis 1396/02/21

Hot tube folliculitis 1396/02/21

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 1396/02/21

Furuncle 1396/02/21

Furuncle 1396/02/21

Furuncle 1396/02/21

Carbuncle Infection of a group of contiguous follicles, with multiple drainage points Sometimes fever 1396/02/21

Carbuncle 1396/02/21

Carbuncle 1396/02/21

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 1396/02/21

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 24-48 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 1396/02/21

Necrotizing fasciitis 1396/02/21

Necrotizing fasciitis 1396/02/21

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 1396/02/21

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 1396/02/21

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 1396/02/21

1396/02/21