皮膚及軟組織感染 新光醫院急診醫學科連楚明 2005-11-25 皮膚及軟組織感染 類丹毒 Erysipeloid: Erysipelothrix rhusiopathie :handle salt water fish. 治療藥物 : PCN, erythromycin Aeromonas hydrophilia: 游泳時傷口感染, 肝硬化, 惡性腫瘤. 傷口及軟組織感染 : 蜂窩組織炎, 猛爆性肌肉壞死. 出血性水泡 Vibrio vulnificus: 水泡性蜂窩組織炎, 海水中受傷, 肝硬化, 高死亡率. 出血性水泡 皮膚及軟組織感染 Impetigo :Group A strept., S. aureus. S.S.S.:S. aureus. charact. by widespread bullae & exfoliation. Furuncle & carbuncle:s. aureus. 丹毒 (Erysipela): Strept. 蜂窩組織炎 (Cellulitis): Strept. & S. aureus. 皮膚及軟組織感染 鏈球菌毒性症候群 (Streptococcal Toxic Shock Syndrome) Invasive Gr A Strept. infection in young adult, 20-50 Y/O. 臨床表徵 : 低血壓, 早期器官衰竭. 肌肉壞死及壞死性肌膜炎, 病程迅速, 30 % 死亡. 治療 : 早期外科引流及擴傷, fasciotomy, 或截肢. 出血性水泡 治療藥物 : Penicillin, clindamycin, ceftriaxone.
皮膚及軟組織感染 壞死性肌膜炎 (Necrotizing Fasciitis) 致病菌 : 以混合感染最常見. G(+): Staphylococcus, GrA streptococcus G(-):Enterobacteriae: E. coli, K. pneumoniae, Salmonella Anaerobes: Bacteroides, Clostridium ( often as sole cause). 死亡率 : 20-47%. 治療 : 馬上外科引流及擴傷. 取膿液馬上做革蘭氏染色 經驗抗生素療法需對抗厭氧菌腸內菌及鏈球菌. Diagnostic aids of NF Microscopic Blood culture Gram stain and culture Tissue culture Triage manifestations of NF Chills Constitutional symptoms Decreased urinary output Fever Mental status change Neuralgia Shock Tachycardia Tachypnea Toxic appearance Weakness/fatigue Diagnostic aids of NF Radiologic CT scan Ultrasound X-ray MRI
Diagnostic aids of NF Histologic Fascial biopsy Fine needle aspiration Frozen section Incisional biopsy Causative organisms in NF (Type 2 NF) Gram-positive bacteria Group A Streptococcus (S. pyogenes) +/- Staphylococcus Causative organisms in NF (Type 1 NF) Treatment Gram-positive bacteria Streptococcus (not group A) Staphylococcus Corynebacterium Gram-negative bacteria Fusobacterium Escherichia Enterobacter Proteus Klebsiella Serratia Pseudomonas Vibrio Shigella Neisseria Pasteurella Salmonella Anaerobes Bacteroides Peptococcus Clostridium Fungi Candida Cryptococcus Histoplasma Broad-spectrum antibiotic coverage Nutritional supplements Hemodynamic support Wound care Prompt surgical debridement
Streptococcal Toxic Shock Syndrome Streptococcal infections gram-positive coccoid bacteria that grow in chains. colonize the skin and mucous membranes of animals On blood agar plates, streptococci may cause complete (beta), incomplete (alpha) or no hemolysis (gamma). B-hemolytic Group A Streptococcus (S. pyogens) Serious streptococcal skin and soft tissue infections Erysipelas Streptococcal Cellulitis Necrotizing Fasciitis (Streptococcal Gangrene) Myositis-Myonecrosis Streptococcal Toxic Shock Syndrome Group A streptococcal infections Pharyngitis Impetigo Scarlet fever Bacteremia Rheumatic fever Post-streptococcal glomerulonephritis Erysipelas, suppurative infections Streptococcal Toxic Shock Syndrome
GAS Ominous sign The portals of entry for streptococci are the pharynx, skin, and vagina in 50% of cases Blunt trauma 50% of cases associated with necrotizing fasciitis progression of soft tissue swelling to vesicles or bullae GAS Infectious route initial 24 hours: swelling, heat, erythema, and tenderness develop and rapidly spread 24 to 48 hours: the erythema darkens, changing from red to purple and then to blue, and blisters and bullae form that contain clear yellow fluid. minor trauma frequently Surgical procedures viral infections such as varicella and influenza penetrating trauma insect bites, slivers burns
Gas Risk Factors 4th or 5th day: purple areas become frankly gangrenous. 7th to the 10th days: dead skin begins to reveal extensive necrosis of the subcutaneous tissue. Patients become may become unresponsive, mentally cloudy, or even delirious. Age (neonates and elderly) Diabetes Alcoholism Surgical procedures Trauma: Penetrating and Nonpenetrating wound Varicella Contact with a patient High prevalence of invasive strains in the community Nonsteroidal anti-inflammatory agents
GAS Diagnosis β-hemolytic Gr A. Streptococcus high or increasing prevalence of M-1 or M-3 strains among throat isolates may increased incidence of Strep TSS in that community DM foot; Gas forming Lip S. aureus
Carbuncle Group A Streptococcus S. aureus K. pneumoniae
Psoas muscle abscess Cutaneous findings include diffuse redness and edema progressing to necrosis and hemorrhagic bullae. Because of this rapid progression, it is important to diagnose and treat NF quickly to decrease mortality. Fasciitis; Aeromonas
Deep neck infection 骨髓炎 成人 : 外傷 : 最常見, 通常為混合感染. 血行感染 : 脊髓. (early involvement of intervertebrae disc) 致病菌 :S. aureus 最常見. 骨髓炎 骨髓炎 小孩 : 急性, 血行感染 位置 : metaphysis of long bone 致病菌 : <1 歲 : S. aureus, Strept. Agalactiae, E. coli. >1 歲 : S. aureus. GAS, H. influenzae. 鐵釘刺到之傷口感染 : 95% 綠膿桿菌所引起.
Psoas muscle abscess Questions? DM foot; Gas forming