Soft Tissue Infections

Skin Infections

Historical Risk Factors

In patients with liver disease, vibrio vinificulis is a risk if eating or working with shellfish or sea water.  Similiar syndrome caused by aeromonas hydrophilia is caused by freshwater

Abx

HIV

IVDA

Splenomegaly

ETOH

heart murmur or any prosthetics

Steroids

Chemotherapy

Diabetes

(from EM Reports)

Cellulitis

Staph and strep pyogenes

Periorbital/orbital usually secondary to sinus infection

Mild is <2cm in adults

Mod/Severe systemic signs or symptoms, labs abnormal, >2cm

 

Need blood cultures only if signs of systemic toxicity.  Blood cultures are usually useless as isolates rarely correlate with actual bug.

Wound cultures if patient is failing to improve on the current antibiotic regimen.  If you do sample, take deep tissue from ulcer base.

 

Treatment

augment c probenicid (inhibits tubular pcn secretion)?

 

Fake nails give pseudomonal infections, Also the pads in any shoes. Rx with Diclox/Bactrim?

Infection in bursa vs. joint, have patient pronate/supinate arm to differentiate

 

Always admit cellulitis overlying a weight bearing joint.

PCN resistant bugs skyrocket if you have a child in daycare

 

Outbreaks of persistent furunculosis on the lower extremities have been reported in patrons of nail salons. The causative organism has been identified as Mycobacterium fortuitum

 

Enterobacter cloacae

think wooden foreign bodies

Impetigo

bullous=staph, otherwise strep.  Thick amber/honey crust

Erisypilas

raised lesions, painful and demarcated

group A strep

Lower ext 70%, Face 20%

Abscesses

I/D

If surrounding cellulitis, needs broad antibiotics

 

Loop Drainage

J Ped Surgery Volume 45, Issue 3, Pages 606-609 (March 2010)The use of loop drains proved safe and effective in the treatment of subcutaneous abscesses in children. Eliminating the need for repetitive and cumbersome wound packing simplifies postoperative wound care. Furthermore, there is an expected cost savings with this technique given the decreased need for wound care materials and professional postoperative home health services. We recommend this minimally invasive technique as the treatment of choice for subcutaneous abscesses in children and consider it the standard of care in our facility.

​loop drainage of abscesses using the cuff of a sterile glove (Journal of Emergency Medicine, 2014-08-01, Volume 47, Issue 2, Pages 188-191)

 

Leishmaniasis

Chronic Non-Healing Ulcers:  if traveler, consider leishmaniasis.  From Sandfly bite.  Cutaneous leishmania is also endemic to SW United States.  Skin is dry, gray and scaly.  Especially seen in immunocompromised players

Erythrasma

intensely pruritic

seen in diabetic males

genitocrural distribution

Looks like candida, but there are no satellite lesions

Under Wood’s lamp, it turns bright red

Treat with Erythromycin

Clostridial Myonecrosis (Gas Gangrene)

Clostridium perfringens is the classic organism responsible for “gas gangrene” or clostridial myonecrosis, although any Clostridial species can produce such infections. Clostridium perfringens is especially likely in wounds contaminated with soil. Clinically, Clostridium infections begin within hours of an inciting trauma, or surgery, with the sudden onset of pain that rapidly extends beyond the wound. A thin, watery discharge may develop, and large hemorrhagic bullae appear. A Gram’s stain of the discharge often reveals gram-positive bacilli with a paucity of white blood cells.

Clostridium septicum can cause spontaneous, nontraumatic necrotizing infections. A colonic lesion, such as carcinoma, will predispose to this highly lethal disease.

 

Toxic Shock Syndrome

Staphylococcal Scalded Skin Syndrome

Scalded skin syndrome often starts in a child with a bullous impetigo. The lesion begins as a vesicle, and then gradually enlarges into flaccid bullae that rupture. New bullae typically appear over the next 2-3 days, during which time hair and nails may also shed. Fever, skin tenderness, and a scarlatiniform rash are common. The exfoliation toxin can be also secreted by localized infection in the nasopharynx, umbilicus, or urinary tract. In some children, exposed dermal surfaces will weep, while fluid and electrolyte losses may lead to hypovolemia. Exposed surfaces may also serve as a portal for other infections. Most children recover in about 10 days if appropriately treated.

Scalded skin syndrome should be treated with parenteral antibiotics. In a community-acquired infection, beta-lactamase-resistant antibiotics are appropriate. When the infection appears to have been acquired in a hospital or extended care facility, methicillin-resistant Staphylococcus aureus should be considered and vancomycin is the drug of choice. Intranasal mupirocin may provide benefits by eliminating intranasal colonization.

Staph Scalded Skin-Nikolsky’s Sign-easy separation of outer skin

Necrotizing Fasciitis (NSTI)

Group A streptococcus, known as the “flesh-eating bacteria” in the lay press, causes a wide spectrum of soft-tissue infections. They range from the mild and superficial, such as impetigo, to a rapidly progressive and deadly necrotizing contagion.

Many of these patients develop hypotension, renal dysfunction, and coagulopathies resembling staphylococcal toxic shock syndrome. The mortality rate remains higher than 30% but with  appropriate antibiotics and supportive care, can be reduced to 12%.

 

Recognition-suspect if pain is out of proportion to clinical findings, then progression to anesthesia.

All present with hypotension, initially or soon afterwards.  Progressing to multiorgan dysfunction.

 

 

Will at first look just like a cellulitis with/without abcess.  One clue is that area will become anesthetic as infection progresses.  May not see bubbles of air on radiography b/c only some organisms will produce.  Not necessarily clostridium if you do see bubbles, e. coli and others can produce as well.  Broad spectrum abx and surgical consult.  Unasyn/Genta or Amp/Genta/Flagyl or Imipenem/Flagyl  Unasyn plus clindamycin

Stat surgical consult

 

• Type I, or polymicrobial NF, usually occurs after trauma or surgery and in diabetics. This form may initially be mistaken for a simple wound cellulitis. However, severe pain and systemic toxicity reflect widespread tissue necrosis underlying apparently viable skin. This disease process may also be observed in association with urogenital or anogenital infections (Wet Areas). Need gram+, gram -, anaerobes.
• Type II, or group A streptococcal NF, is the so-called flesh-eating bacterial infection. Extremities in non-diabetics. Need only Gram+ treatment. Perhaps 5th gen cephalosporin is optimal agent with 24 hours of clinda.
• Type III NF, or clostridial myonecrosis, is gas gangrene. This skeletal muscle infection may be associated with recent surgery or trauma.

Type II — Type II necrotizing fasciitis is caused by GAS and was previously called “streptococcal gangrene” [ 7]. There was a dramatic increase in the number of invasive infections such as necrotizing fasciitis caused by GAS during the 1990s. In Ontario, Canada, for example, the incidence of GAS necrotizing fasciitis increased from 0.085 per 100,000 in 1991 to 0.40 per 100,000 in 1995 [10] . Most cases were community-acquired but 20 percent were nosocomial or acquired in a nursing home. Almost one-half had streptococcal toxic shock syndrome. ( See “Streptococcal toxic shock syndrome”). That most cases are community-acquired is further supported by a recent epidemic in a small town in Minnesota where the incidence approached 24 cases/100,000 population. In contrast to type I necrotizing fasciitis, which primarily occurs in patients who are immunocompromised or have certain chronic diseases such as diabetes, type II can occur in any age group and among patients who do not have complicated medical illnesses [9]. Predisposing factors include a history of blunt trauma, varicella (chickenpox), injection drug use, a penetrating injury such as laceration, surgical procedures, childbirth, exposure to a “case,” and perhaps nonsteroidal antiinflammatory drugs.

The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: a tool for distinguishing necrotizing fasciitis from other soft tissue OBJECTIVE: Early operative debridement is a major determinant of outcome in necrotizing fasciitis. However, early recognition is difficult clinically. We aimed to develop a novel diagnostic scoring system for distinguishing necrotizing fasciitis from other soft tissue infections based on laboratory tests routinely performed for the evaluation of severe soft tissue infections: the Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score. DESIGN: Retrospective observational study of patients divided into a developmental cohort (n = 314) and validation cohort (n = 140) SETTING: Two teaching tertiary care hospitals. PATIENTS: One hundred forty-five patients with necrotizing fasciitis and 309 patients with severe cellulitis or abscesses admitted to the participating hospitals. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The developmental cohort consisted of 89 consecutive patients admitted for necrotizing fasciitis. Control patients (n = 225) were randomly selected from patients admitted with severe cellulitis or abscesses during the same period. Hematologic and biochemical results done on admission were converted into categorical variables for analysis. Univariate and multivariate logistic regression was used to select significant predictors. Total white cell count, hemoglobin, sodium, glucose, serum creatinine, and C-reactive protein were selected. The LRINEC score was constructed by converting into integer the regression coefficients of independently predictive factors in the multiple logistic regression model for diagnosing necrotizing fasciitis. The cutoff value for the LRINEC score was 6 points with a positive predictive value of 92.0% and negative predictive value of 96.0%. Model performance was very good (Hosmer-Lemeshow statistic, p =.910); area under the receiver operating characteristic curve was 0.980 and 0.976 in the developmental and validation cohorts, respectively. CONCLUSIONS: The LRINEC score is a robust score capable of detecting even clinically early cases of necrotizing fasciitis. The variables used are routinely measured to assess severe soft tissue infections. Patients with a LRINEC score of > or = 6 should be carefully evaluated for the presence of necrotizing fasciitis. (Crit Care Med. 2004 Jul;32(7):1535-41)

 

derivation of a CT scan score (J trauma 2011;

Validation parameters for a score of >6 points included sensitivity (86.3%), specificity (91.5%), negative predictive value (NPV) (85.5%), and positive predictive value (PPV) (63.3%). Validation parameters for fascial air alone yielded a sensitivity of 44.1%, specificity 61.1%, NPV 35.2%, and PPV 58.9%. The mean scores of the NSTI and non-NSTI group were 8.57 (±1.22) and 2.74 (±0.65), respectively.

HBO decreased mortality in this retrospective study (Intensive Care Medicine Volume 38, Number 7 (2012), 1143-1151)

Ultrasound STAFF Exam (West J Emerg Med 2014;15:111)

• subcutaneous thickening
• air
• fascial fluid

 

Pyomyositis

J Am Acad Derm (2004;51:308)

Deep space infection of skeletal muscle, without overlying cellulitis. Causative agents are usual skin bacteria

pelvis, hip, or leg

usually, but not always, have some increased risk of infection

MRI or CT scan

2/3 of pts will need surg drainage

 

Diabetic Foot

Screen for Osteo

get an x-ray

probe to bone

Elevated ESR has a sensitivity and specificity in the 80s for detecting osteomyelitis (Majeed, et. al, 2019)

Get an MRI if you have a suspicon

Vascular Assessment

The WIfI (Wound, Ischemia, and Foot Infection) scoring system uses the results of the non-invasive vascular studies and other factors to help predict who would benefit from revascularization and who is at greater risk for amputation (JVS Practice Guideline Mills, Sr., et. al, 2014).  Clinicians can synthesize this information to discuss severity of illness and possible treatment plans with their patients.

Wound Swabs

The results of a superficial wound swab do not correlate with the pathogen causing infection. Clinicians should avoid superficial swab specimens and opt for a specimen obtained from deep tissue, often at the time of debridement (IDSA Guidelines Lipsky, et. al, 2012).

 

Cipro/clinda is very good combination

 

Enterobacter cloacae

think wooden foreign bodies

 

Waterborne Skin Infections

Vibrio vulnificus

a free-living, gram-negative, curved bacillus found in warm marine waters. It is capable of causing terrifying life- and limb-threatening infections, especially in those with underlying liver disease (usually due to alcoholism or viral hepatitis). Skin infection may follow exposure of open wounds to contaminated seawater or shellfish or may spread hematogenously following ingestion of contaminated seafood, usually raw oysters. Skin involvement may range from mild cellulitis to rapidly progressing necrotizing fasciitis and myositis. Patients may develop hemorrhagic bullae. Treatment requires prompt recognition, surgical debridement, and early institution of antimicrobial therapy. Clinical trials are lacking, but some authors recommend third-generation cephalosporins (e.g., ceftazidime) with an aminoglycoside. Others suggest adding doxycycline to the empiric antibiotic regimen based on animal studies and in vitro susceptibility testing

 

3rd generation cephalosporin + tetracycline may be best choice. retrospective article Arch Intern Med 2006;166:2117-2123.

Aeromonas Hydrophila

gram-negative bacillus found in freshwater lakes and streams. Serious soft-tissue infection may follow wound exposure to such water. These suppurative infections progress rapidly, often requiring surgical drainage. Cephalosporins (second-, third-, or fourth-generation), trimethoprim/sulfamethoxazole, and fluoroquinolones are active against Aeromonas

Mycobacterium marinum

develops following exposure to contaminated water and is generally seen in swimmers and fishermen. A small papule, or nodule, develops after 2-6 weeks of incubation. This “fish tank” or “swimming pool” granuloma will then ulcerate and drain serosanguinous fluid. In approximately 20%-40% of patients, nodular lesions develop along the lymphatics (known as the “sporotrichoid” distribution). Bacterial culture may require 2-4 weeks of incubation.

M. marinum is resistant to isoniazid and pyrazinamide. Treatment options include clarithromycin, minocycline, or trimethoprim/sulfamethoxazole as single agents, or a combination of ethambutol and rifampin. The duration of antimicrobial therapy is approximately 12-24 weeks, and surgical debridement is often required

 

Fire Coral:  local reactions

Sponges:  abrasions with mild toxin

Marine Worms:  local wound care

Breast Disorders

Trauma

Hematoma

If infected, I/D

Mondor’s Disease

phlebitis of thoracoepigastric vein (runs from axilla to epigastrum)

Rx only needed for pain control

Subcutaneous Rupture

usually from seatbelt trauma

Infectious

if in non-lactating woman, consider malignancy

Milk Stasis

Mastitis

Epidemic-nosocomial ~1st week of life.  Usually progresses to abcess. Spread from infant to infant and then to mother.  Staph.  Use diclox.  If abcess, aspiration and possible surgical drainage along with parenteral antibiotics.  Do not breast feed from that side.

Endemic-usually more benign.  1-2 weeks.  Staph/strep.  Must continue to feed from that breast.  Moist heat pads.  Oral abx (keflex or diclox)  unless systemic symptoms

Mastodynia

cyclical breast pain

Drugs and Breast Feeding

avoid flagyl, sulfonamides, nitrofurantoin, ergotamine, lithium, Hold breast feeding for 4 days after radioactive compounds.

 

Emerging MRSA

MRSA susceptibilities were as follows: 100 percent were susceptibleto trimethoprim–sulfamethoxazole (217 of 217) and to rifampin (186 of 186); 95 percent were susceptible to clindamycin (215of 226), 92 percent to tetracycline (207 of 226), 60 percentto fluoroquinolones (106 of 176), and 6 percent to erythromycin(13 of 226). Although the proportion of all S. aureus isolates(MRSA and MSSA) that were resistant to clindamycin was lessthan 15 percent at 10 of the study sites, 6 of 10 S. aureusisolates from New York City (60 percent) were resistant to clindamycin.Among the isolates that were sent to the CDC, 11 of 218 MRSAisolates (5 percent) and 7 of 55 MSSA isolates (13 percent)were not susceptible to clindamycin, including 4 (2 percent)MRSA isolates and 5 (9 percent) MSSA isolates with inducibleclindamycin resistance detected by an antimicrobial-susceptibilityD-zone disk-diffusion test. Sixty-six patients with MRSA infections(27 percent) had one or more established risk factors for healthcare–associated MRSA; these included 43 patients who hadbeen hospitalized within the past year, 28 with a history ofMRSA infection, 2 who resided in a long-term care facility,and 1 who was undergoing dialysis. Isolates from 55 of thesepatients were evaluated at the CDC, and 54 (98 percent) hadpulsed-field types characteristic of community-associated MRSA.

Features associated with the isolation of MRSA as compared with the isolation of any other bacteria (Table 2) included antibioticuse in the month before enrollment, the presence of an abscessor a lesion attributed to a spider bite at enrollment, historyof MRSA infection, and a recent history of close contact withsomeone with a similar skin infection. The presence of an underlyingillness and characterization as belonging to the “other” categoryof race or ethnic background were negatively associated with the isolation of MRSA. In multivariate logistic-regression analyses, all these factors were associated with MRSA infection, withthe exception of the presence of an abscess (Table 3). Blackrace was independently associated with MRSA infection. Controllingfor study site did not affect the association between any of these factors and MRSA infection. Among 64 patients with noneof these factors, 31 (48 percent) were infected with MRSA. Theonly factor that was significantly associated with isolationof MRSA, as compared with MSSA, was the presence of abscessat enrollment (odds ratio, 2.3; 95 percent confidence interval,1.2 to 4.4).

(NEJM 2006;355(7):666)

 

 

Approach to Suspected Staphylococcal Infections.

For wound cultures that are positive for community-associated MRSA (usually not a multidrug-resistant phenotype), in vitro susceptibility to trimethoprim–sulfamethoxazole (TMP-SMX), tetracycline, erythromycin, clindamycin, and vancomycin should be assessed. If the isolate is resistant to erythromycin but susceptible to clindamycin, the clindamycin D-zone test should be performed if clindamycin therapy is being considered.10 For wound cultures that are positive for health care–associated MRSA (usually a multidrug-resistant phenotype), in vitro susceptibility to vancomycin, rifampin, and linezolid should be assessed. Assessment of susceptibility to daptomycin and quinupristin–dalfopristin is not necessary unless therapy with these agents is being considered. Susceptibility to fusidic acid may be assessed in countries where this agent is available. Empirical antibiotic therapy should be reviewed once susceptibility data are known. For methicillin-susceptible S. aureus (MSSA), antistaphylococcal penicillin or a first-generation cephalosporin (1-CEF) may be suitable. For community-associated MRSA, TMP-SMX, clindamycin, or tetracycline may be suitable. For health care–associated MRSA, vancomycin, linezolid, daptomycin, or rifampin plus fusidic acid may be suitable.

 

 

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