Pocket Emergency Medicine (Pocket Notebook Series) 3rd Ed.

Cutaneous Abscess (Clin Infect Dis 2005;41(10):1373)

History

• ↑ pain, tenderness & induration, usually w/o h/o fever or systemic tox

• Disruption of skin from trauma or penetrating injury, often pt cannot recall injury

• H/o IVDA/skin popping, prior MRSA abscesses

Findings

• Exquisitely tender, soft, fluctuant mass surrounded by erythema

• Most commonly Staph species, often polymicrobial

Evaluation

• Blood work rarely needed unless appear systemically ill; US may help w/ localization

• Culture from abscess only if tx w/ abx, severe infection, systemic illnesses, failed initial tx

Treatment

• No abx indicated in healthy hosts unless cellulitis, fever, immunosuppression, failed I&D

• I&D w/ regional nerve or field block ± procedural sedation

• Create elliptical incision to prevent premature wound closure

• Break up loculations in abscess cavity w/ hemostat

• Consider irrigate & pack w/ 1/4-in gauze × 48 h (24 h if cosmetically important)

• If surrounding cellulitis, nafcillin 2 g IV q4h, cefazolin 1 g IV q8h, or cephalexin PO

• If for complicated abscess: Clindamycin, Bactrim, tetracycline, linezolid, vancomycin

Disposition

• D/c w/ wound care instructions, 2-d f/u

• Warm soaks TID × 2–3 d after removal of packing to allow continued wound drainage

Pearl

• Can develop essentially anywhere: Furuncle, acne, skin breakdown, insect bites

• Routine packing of abscesses after I&D is controversial

Paronychia

History

• Pain & swelling lateral to nail edge; superficial infection of epithelium

• No inciting injury but can be secondary to contaminated nail care instruments or trauma

Findings

• Purulent collection lateral to nail bed w/ minimal surrounding erythema

• Most commonly Staph or Strep species but can have mixed aerobic & anaerobic flora

Evaluation

• No labs necessary

Treatment

• No abx indicated in healthy hosts

• Digital block w/ 1% lidocaine with or without epinephrine in each web space of affected digit

• #11 blade scalpel to lift cuticle from nail on affected side & express purulent material

Disposition

• D/c w/ wound care instructions, 2-d f/u

• Warm soaks to finger TID × 2–3 d to allow complete drainage

Pearls

• Often h/o manicure/pedicure, nail biting

• If recurrent or chronic paronychia, consider Candida infection

• May spread to pulp space of finger (felon) or deep spaces of hand, tendon if neglected

Pilonidal Cyst

History

• Painful, tender abscess in alar cleft, often in obese or hirsute individuals

• More prevalent in males; fever & systemic tox very rare

Findings

• Painful, localized abscess in natal cleavage/midline sacrococcygeal region, 4–5 cm posterior to anal opening; surrounding erythema & fluctuance

• Mixed flora: Staph or Strep species, anaerobic cocci, mixed aerobic & anaerobic flora

Evaluation

• No labs necessary unless systemically ill

Treatment

• Same as for cutaneous abscess, I&D

• Surgical referral for excision of follicle & sinus tract after acute episode subsides

Disposition

• D/c w/ wound care instructions, 2-d wound care f/u

Pearls

• High recurrence rate (40–50%) unless follicle surgically removed

• Thought to be caused by hair penetrating into subcutaneous tissues creating abscess

Bartholin Gland Cyst/Abscess

History

• Severe localized pain in labia caused by obstructed Bartholin duct

• Difficulty walking & sitting secondary to pain

• Fever & signs of systemic tox are rare

Findings

• Painful, tender, cystic mass on inferior lateral margin of vaginal introitus, often w/ purulent drainage from sinus tract

• Typically anaerobes, MRSA, also Staph, Strep, & E. coli species, chlamydia, gonorrhea

Evaluation

• Culture for chlamydia, gonorrhea

Treatment

• I&D through mucosal surface, place Word catheter ×48 h

• Sitz baths TID for the 1st 2–3 d to assist drainage

• Gyn f/u for consideration of marsupialization to prevent recurrence

Disposition

• D/c w/ wound care instructions, 2-d wound care f/u

Pearl

• Recurrence rate still 5–15% after marsupialization; consider gyn malignancy

History

• Pain & swelling in rectal area w/ defecation & often w/ sitting down or walking

• High fever & signs of systemic tox are rare

• Pts often have h/o Crohn dz, obesity, DM, or PID

Findings

• Rectal exam essential to ensure abscess localized outside of anal sphincter & to identify upper extent of abscess

• Typically E. coli species, Enterococcus, Bacteroides species, S. aureus, MRSA

Figure 4.1.

Evaluation

• Lab studies unnecessary unless systemically ill

• DM or immunocompromised should have Chem, CBC

• CT/MRI if concern for intersphincteric or supralevator or postanal abscess or fistula

Treatment

• ED I&D of superficial abscesses outside the anal verge w/ visible indurated area

• Pain control; I&D extremely painful, procedural sedation often needed

• If abscess is only identified on rectal exam & no induration visible, refer to surgery for I&D under general anesthesia

• DM or immunocompromised pts should undergo I&D in OR to ensure full drainage

• Pack w/ Vaseline gauze ×48 h, Sitz baths TID for 1st 2–3 d to assist drainage

• No abx for healthy host w/ superficial abscess

• Consider abx for immunocompromised, prosthetic device/valve, incomplete I&D

• Levofloxacin 500 mg QD (ampicillin 1 g + gentamicin 80 mg q8h) + metronidazole 500 mg q8h, consider vancomycin

Disposition

• D/c w/ wound care instructions, 2-d wound care f/u

• Admit diabetic & immunocompromised for IV abx

Pearls

• 35–50% treated w/ I&D or spontaneous drainage will develop chronic anal fistula

• Bilateral tenderness raises possibility of “horseshoe” abscess

History

• Caused by contiguous spread (sinus, ear, dental), hematogenous seeding from distant infection, (endocarditis) or post-CNS surgery/penetrating trauma

• HA (70–90%), fever (50%), meningismus, photophobia, sz (30%), vomiting (25–50%), AMS

• Subacute time course (vs. meningitis or encephalitis)

Findings

• Focal neuro deficits, low-grade fever, obtundation (mass effect), sz, AMS, nuchal rigidity (25%), papilledema (10–50%)

• Wide variety of organisms depending on method of entry, 1/3 polymicrobial

Evaluation

• Blood cultures, CBC (WBC nonspecific), Chem, coags

• CT scan w/ & w/o IV contrast; MRI more sens for cerebritis, posterior fossa lesions

• CSF findings nonspecific, avoid LP

Treatment

• Emergency neurosurgical consult for drainage in OR; airway management, sz tx

• Early IV abx w/ good CSF penetration, tailored to likely pathogen

• Start broad-spectrum IV abx: Ceftriaxone 2 g + vancomycin 1 g + metronidazole 500 mg

• Corticosteroids ONLY for tx of cerebral edema: Decadron 10 mg IV × 1 then 4 mg q6h

Disposition

• Neurosurgical intervention for operative washout, 6–8 wk IV abx then 4–8 wk PO abx

Pearls

• Mortality 24–27%, unless abscess ruptures into ventricular system (mortality 80%)

• Morbidity from residual neuro deficits, new sz from scar tissue or neuropsych Δ (50%)

SOFT TISSUE INFECTIONS

Approach

• Careful hx, associated sxs (V/D, cough, abd pain, AMS), progression

• Check blood sugar if diabetic

• Assess VS for significant abnormalities that may indicate serious infection (↓ BP, ↑ HR)

• If immunosuppressed (HIV/AIDS, elderly, malnourished, chronic steroids) or neutropenic, more intensive eval & testing: CBC, Chem, UA & cx, CXR; consider blood cx & admission

• If recent foreign travel: Consider travel-related infectious etiologies

Cutaneous/Subcutaneous Cellulitis (Clin Infect Dis 2005;41(10):1373)

History

• Often no h/o broken skin; ± local trauma, recent surgery, FB

• May report fever, chills, malaise

Findings

• Warm, blanching erythema & tenderness to palpation, mild to moderate swelling

• ± distal skin disruption (eg, tinea pedis b/w toes w/ cellulitis of anterior shin)

Evaluation

• If elevated BS, check Chem, UA; Rule out abscess clinically or with bedside ultrasound

• Consider blood cultures, CBC w/ differential, chemistries, CRP, CPK in systemically ill pts

• Bacterial cultures of inflamed area not indicated; only 10–50% positive

• Most often caused by Strep or S. aureus (including MRSA); can be from metastatic seeding

Treatment

• If LE cellulitis, recommend rest & elevation × 48 h, crutches if needed

• PO abx: cephalexin 500 mg PO QID, dicloxacillin 500 mg PO QID, or Augmentin 500 mg PO TID

• IV abx: Cefazolin, ceftriaxone, nafcillin

• If PCN allergic: clindamycin 500 mg PO QID, or azithromycin 500 mg PO × 1, then 250 mg PO × 4 d, levofloxacin 500 mg QD × 5 d

• If diabetic or immunocompromised, use broader coverage abx

• Consider MRSA coverage: Vancomycin, gentamicin, tetracyclines, Bactrim, rifampin, Daptomycin, linezolid

• Pain control w/ NSAID/APAP; if severe pain consider necrotizing infection

• Wound débridement if infected, contaminated or devitalized wound

• Surgery consult if aggressive/necrotizing infection/gas in soft tissue

Disposition

• D/c w/ PO abx & 24–48 h f/u, strict return instructions

• Admit if signs of systemic infection, DM, immunocompromise, failure of outpt tx

Pearls

• Due to inflammation of dermal & subcutaneous tissue due to nonsuppurative bacteria, infection does not involve fascia or muscles

• Consider Doppler vascular studies in single limb w/ diffuse swelling, posterior calf or medial thigh to rule out DVT

• Mark border w/ permanent ink, write time & date

Erysipelas

History

• Extremes of age, obesity, DM, CHF, postop, nephrotic syndrome at higher risk

• Acute onset pain, erythema, induration

• Initial fever & chills followed by painful rash 1–2 d later

• May have systemic sxs: Myalgias, arthralgias, nausea, HA

Findings

• Skin painful superficial, indurated, raised; erythema w/ sharply demarcated border

• Irregular erythema w/ lymphangitis, may see desquamation, dimpling, vesicles, LAD

• 70–90% found on lower extremities, 5–20% on face, 5–6% on upper extremity

Evaluation

• None indicated unless toxic appearing

Treatment

• PCN G, amoxicillin, cefazolin 1 g IV q8h or azithromycin 500 mg PO

• PCN allergic: Azithromycin, clindamycin, levofloxacin

Disposition

• D/c w/ PO abx & analgesics, elevate affected area, 24–48 h f/u, strict return instructions

Pearls

• Typically caused by group A β-hemolytic streptococcus; involves dermis, hypodermis, & lymphatics

• More superficial than cellulitis

• Recurrence rate 10–40%

Staphylococcal Scalded Skin Syndrome (SSSS) (Am J Clin Dermatol 2003;4(3):165)

History

• Young children <5 yr, rare in adults, fairly rapid progression of prodromal sore throat, conjunctivitis, fever, malaise to painful red skin w/ sloughing

Findings

• No mucous membrane involvement (vs. TEN)

• Erythematous cellulitis followed by acute exfoliation: Bullae, vesicles → large sheets of skin loss resulting in scalded-appearing skin

• General malaise, fever, irritability, tenderness to palpation, does not appear severely ill

Evaluation

• None indicated unless systemically ill

• Positive Nikolsky sign (epidermis separates when pressure applied)

Treatment

• Similar to burns (IVF, topical wound care, burn consult)

• Most recover w/o abx but still recommended: Nafcillin, vancomycin, clindamycin

Disposition

• Admit for burn care, IVF; consider ICU

Pearls

• Caused by exfoliative exotoxins of S. aureus, reports of MRSA

• Separation of epidermal layers vs. more severe TEN (necrosis at level of basement membrane)

• Prognosis: Children (4% mortality) often w/o significant scarring; adults (60% mortality)

Toxic Shock Syndrome (TSS)

History

• Multiple sxs: Prodrome, pain at site of infection (out of proportion to findings), fever, chills, N/V, abd pain, watery diarrhea, myalgias, arthralgias, pharyngitis, HA, AMS

• Recent surgery, infrequently changed packing (tampons, nasal packing)

Findings

• Clinical Dx w/ findings from all organ systems:

• Temp >38.9°C, ↓ BP (shock/hypovolemia), rash

• “Sandpaper” diffuse, macular rash initially on trunk → spread to arms, legs, palms, soles → flaking full-thickness desquamation, 5–12 d after onset

• Involvement of 3 organ systems (see table)

Evaluation

• CBC w/ differential, Chem, UA, LFTs, coags, cultures (blood, urine, throat)

Treatment

• Remove tampon or packing if still in place, drain abscesses if present; burn care

• Aggressive resuscitation, pressors if needed, Foley catheter to monitor urine output

• Abx, may not have impact (toxin-mediated process); tx any identified source

• Nafcillin, vancomycin, clindamycin to suppress bacterial toxin synthesis; linezolid

• High-dosed steroids reported to improve TSS in case reports

• IVIG 400 mg/kg IV (has antibodies to TSS-1 & other exotoxins) for very ill pts w/ pulmonary edema or who require mechanical ventilation may reduce mortality

• Surgical consult if debridable sources of infection

Disposition

• ICU admission

Pearls

• Rate ↓ w/ ↓ in use of superabsorbent tampons

• Caused by inflammatory response to TSST-1 enterotoxin from Strep & Staph species

• Strep: Usually after surgery or trauma; scarlet fever-like rash; 30–70% mortality, fulminant

• Staph: More indolent, 5% mortality

• Poor prognosis, mortality as high as 70%, 30–50% recurrence, most w/i 2 mo

Necrotizing Fasciitis

History

• H/o mild trauma, often diabetic, PVD, EtOH abuse or nutritionally compromised

• Sudden onset of pain & swelling which progresses to anesthesia

Findings

• Fever, tenderness, erythema, toxic appearing

• Pain out of proportion to exam &/or numbness, crepitus

• Rapidly spreading, progressive erythema/infection of deep fascia w/ secondary necrosis of subcutaneous tissues, subcutaneous air (due gas-forming organisms)

• Can progress to involvement of deeper layers, causing myositis or myonecrosis

Evaluation

• CBC w/ differential, Chem, UA, CRP, coags

• Plain radiographs less sens than CT in eval of gas w/i soft tissue

Treatment

• Early surgical consult for débridement (definitive tx); hemodynamic support

• Early & broad abx

• Vancomycin 1 g q12h + piperacillin/tazobactam 4 g IV q6h + clindamycin 600 mg IV q8h

• Consider hyperbaric oxygen tx, IVIG after débridement

Disposition

• ICU admission for surgical débridement, transfer for hyperbaric oxygen therapy

Pearls

• Mortality 20–50%, fatal if untreated

• Mostly S. pyogenes (group A), S. aureus, or mixed Gram + & – bacteria, anaerobes

Fournier Gangrene

History

• Elderly, obesity, diabetic, chronic EtOH abuse, chronic steroids, immunocompromised

• Recent h/o instrumentation, indwelling catheter, perirectal dz, anal intercourse

• Fever, lethargy prodrome

• Rapidly progressing scrotal swelling, pain, erythema, warmth, possible purulent drainage

Findings

• Intensely tender, swollen, warm scrotum w/o clear fluctuance, pruritic genitalia

• Fever, chills, systemic sxs (tachycardia, ↓ BP), ± crepitus, drainage

• Deep-space infection is often vastly greater than skin involvement would suggest

Evaluation

• CBC w/ differential, Chem, blood & urine cx, CRP, coags

• X-rays may show subcutaneous air; CT will show extent of infection & necrosis

Treatment

• Urology or general surgery consult for wide débridement & drainage

• Hemodynamic support & resuscitation w/ IVF, pressors

• Broad-spectrum abx: Vancomycin, Unasyn, Zosyn, clindamycin; Td prophylaxis

• Consider hyperbaric oxygen tx. IVIG after débridement.

Disposition

• ICU admission for surgical débridement, transfer for hyperbaric oxygen therapy

Pearls

• Mortality of severe infection 50%; early surgical débridement most strongly correlated w/ outcome

• Polymicrobial (E. coli, Bacteroides, Strep, Staph, anaerobes, enterobacter, fungi)

• Rapid destruction of fascial planes

Periorbital/Preseptal Cellulitis

History

• Recent infection of sinuses, periorbital skin, trauma to periorbital area, bites

Findings

• Unilateral eyelid swelling, erythema, warmth, discoloration of skin

• Injected sclera, conjunctival ecchymosis

• No pain w/ or ↓ extraocular movements, no proptosis

Evaluation

• CBC w/ differential, blood cultures, CT scan of orbits to evaluate for orbital extension

Treatment

• Head elevation

• Abx: Ceftriaxone or Unasyn 3 g IV q6h (if need admission) or cephalexin, dicloxacillin, clindamycin or Augmentin 500 mg PO TID × 10 d if d/c

Disposition

• Admit if appears systemically ill or has other comorbidities

• O/w d/c w/ close ophthalmology f/u (2 d)

Pearls

• Infection of soft tissue of eyelids & periocular region anterior to orbital septum

• Most often caused by Staph & Strep, rarely H. influenzae

• Distinguish from orbital cellulitis: No pain w/ EOM or proptosis in periorbital cellulitis

Orbital Cellulitis

History

• Orbital pain increased w/ extraocular movements, ↓ vision

• Recent infection of sinuses, periorbital skin, trauma to periorbital area, facial trauma

Findings

• Fever, HA, rhinorrhea, malaise

• Proptosis & ophthalmoplegia are cardinal signs

• Unilateral eyelid swelling, erythema, warmth, discoloration of skin

• Injected sclera, chemosis

• Tenderness on gentle globe palpation, ↑ IOP

• ↓ visual acuity, relative afferent pupillary defect, visual field abnormalities

Evaluation

• CBC w/ differential, CT scan of orbits, soft tissue aspirate if possible, blood cultures

Treatment

• Ophthalmology consult, head elevation

• Aggressive tx w/ immediate abx: Vancomycin, Unasyn 3 g IV q6h

Disposition

• Admission for abx

Pearls

• Infection of soft tissues of orbit posterior to orbital septum

• Most common: Strep, Staph, H. influenzae, polymicrobial

• Serious: Venous drainage via communicating vessels w/ the brain (cavernous sinus); most commonly caused by extension from ethmoid sinuses

• Cx: 1.9% meningitis, permanent ocular mobility, visual acuity impairment

Ludwig Angina

History

• Pts w/ poor dental hygiene, recent dental extraction, tooth abscess, penetrating injury

Findings

• Odynophagia, dysphagia, neck swelling, malaise, fever, stridor, drooling, tongue protrusion

• Swelling of submandibular/sublingual space feels hard & “board like” or woody

Evaluation

• CBC w/ differential, Chem, UA, blood cultures, coags

• CT scan head & neck

Treatment

• If severe swelling, aggressively ↑ infection, or airway threatening, endotracheal intubation may be difficult, fiberoptic nasotracheal intubation may be the best initial approach w/ cricothyrotomy as backup

• Consultation w/ otolaryngologist for admission

• IV abx: PCN, Unasyn, 3rd-generation cephalosporin, carbapenems, clindamycin, metronidazole

• Add gentamicin in DM, vancomycin in IVDU

Disposition

• Admit to ICU for IV abx, airway watch

Pearls

• Rapidly spreading, firm indurated cellulitis originally intraorally, involves supramylohyoid & inframylohyoid bilateral w/o abscess or LAD, causing rapid upper airway obstruction

• Surgical débridement was tx in preantibiotic era; now only if unresponsive to IV abx or e/o purulent collections