II. Definitions
- Furuncle (Boil, Abscess)
- Walled-off Nodule of purulent infection forming around a Hair Follicle
- Firm wall with inner fluctuant core
- Carbuncle
- Coalition of Furuncles
- Deeper, more extensive involvement
- Require greater degree of Debridement
III. Pathophysiology
- Hair Follicle infection that spreads to deeper tissue (often begins as Folliculitis)
- Abscess may also form from Cellulitis, or Cellulitis may form from abscess
IV. Risk Factors
- Obesity
- Impaired Neutrophil function
- Corticosteroid use
- Diabetes Mellitus
- Intravenous Drug Abuse
V. Causes
- Staphylococcus aureus (most common)
- Streptococcus species
- Mixed Bacterial Infection
VI. Signs
- Tender, erythematous Skin Mass
- Often spontaneously opens and drains to skin surface
- Distribution
- Precautions
- If IV Drug Abuse is suspected, consider Bacterial Endocarditis (e.g. auscultate for cardiac murmur)
VII. Imaging: Bedside Ultrasound (Point of Care Ultrasound)
- Conflicting efficacy in studies
- Ultrasound may alter clinical management by identifying occult abscess (occurred in 50% of cases in one study)
- Ultrasound is more accurate than clinical exam in one study
-
Ultrasound adds little to abscess diagnosis and localization in one study
- ED clinicians were as accurate with physical examination as with Ultrasound (87% Test Sensitivity and 71% Test Specificity)
- Consider in unclear presentations
- But Ultrasound only 77% Test Sensitivity, 64% Test Specificity in theses cases in this study
- Marin (2013) Acad Emerg Med 20(6): 545-53 [PubMed]
VIII. Management: Acute Episode
- Trial of warm compresses for small abscesses
-
Incision and Drainage
- Primary, definitive, most critical step in Skin Abscess management
-
Antibiotic indications (in addition to Incision and Drainage)
- Antibiotics are usually not required for an isolated abscess without Cellulitis once the lesion is incised and drained
- Antibiotics do not shorten course of abscess
- However recurrence rate may be less with Antibiotic use
- Antibiotic indications (post-drainage)
- Cellulitis (see Cellulitis for Antibiotic choices)
- Serious comorbidity such as Diabetes Mellitus, Immunosuppression or extremes of age
- Multiple sites of infection
- Systemic symptoms
- Rapid progression with concurrent Cellulitis
- Infection involving face, hand or genitalia
- Associated septic phlebitis
- Unreliable follow-up
- Large abscess (e.g. 5 cm and greater, Carbuncle)
- Failure to improve after Incision and Drainage
- Antibiotics for Skin Abscess with Cellulitis (in addition to Incision and Drainage)
- See Cellulitis Management
- As noted above, Antibiotics are not needed for simple abscess without Cellulitis
- Agents for MRSA
- Trimethoprim Sulfamethoxazole (Septra, Bactrim) DS orally twice daily for 5-10 days
- Doxycyline 100 mg orally twice daily for 5-10 days
- Clindamycin 300 mg (or 450 mg if BMI>40) rally three times daily for 5-10 days
- Linezolid 600 mg orally twice daily for 5-10 days
- Vancomycin 15 mg/kg every 12 hours
- Agents for known MSSA
- Dicloxacillin 500 mg orally three to four times daily for 5-10 days
- Cephalexin (Keflex) 500 mg orally three to four times daily for 5-10 days
- Nafcillin (or Oxacillin) 1 g IV every 4 hours
- Cefazolin (Ancef) 1 g IV every 8 hours
- References
- (2017) Sanford Guide, Skin Abscess (accessed 1/1/2018 on IOS app)
- Antibiotics are usually not required for an isolated abscess without Cellulitis once the lesion is incised and drained
IX. Management: Recurrent Abscess
- Optimize personal hygiene
- Regular bathing and Hand Washing with soap and water or Alcohol-based hand cleansers
- Reduce transmission risk
- Active Skin Infections should be cleaned and covered with a dry dressing at least daily (or more as needed)
- Avoid sharing personal items (razors, towels, wash cloths and other linens)
- Wash high contact surfaces (e.g. doorknobs, counters, toilet seats) with commercial cleansers
- Consider differential diagnosis
- Methicillin Resistant Staphylococcus Aureus
- Retained Foreign Body (or prior surgical procedure, esp. mesh)
- Hidradenitis Suppurativa (groin and axilla)
- Pyoderma Gangrenosum (groin, legs)
- Inflammatory Bowel Disease with enterocutaneous fistula (groin, abdominal wall)
- Immunodeficiency (e.g. poorly controlled Diabetes Mellitus, Phagocytosis Disorders)
-
Mupirocin (Bactroban)
- Apply intranasally bid for 5 days
- Reduces nasal Staphylococcus aureus carriage
- Antiseptic body cleansers (e.g. Hibiclens or dilute bleach bath)
- Hibiclens
- Wash completely with Hibiclens daily for 5-14 days
- Dilute bleach bath
- Dilute bleach: 1 teaspoon bleach per gallon water OR
- One quarter cup bleach per 20 gallons water (or 1/4 tub of water)
- Soak in the dilute bleach for 15 minutes twice weekly for 3 months
- Shower to rinse off bleach completely
- Make certain to rinse and dry feet before walking across carpet (and bleaching the carpet)
- Dilute bleach: 1 teaspoon bleach per gallon water OR
- Hibiclens
- Other measures with minimal evidence (not recommended)
- Systemic Antibiotic protocols (10 day course)
- Not generally recommended (poor efficacy, increased resistance rates)
- Rifampin 600 mg PO qd and
- Trimethoprim-Sulfamethoxazole (Bactrim, Septra) DS twice daily
- Clindamycin four times daily
- Vitamin C 1 gram per day
- Effective in those with impaired Neutrophil function
- Systemic Antibiotic protocols (10 day course)
X. Complications
- Cellulitis
- Gangrene
- Necrotizing Fasciitis
- Hidradenitis Suppurativa
- Recurrent Furunculosis
XI. References
- Chan (2014) Crit Dec Emerg Med 28(9): 2-7
- Derksen in Pfenninger (1994) Procedures, p. 50-3
- Gilbert (2002) Sanford Guide, p. 36-37
- Carroll (1996) Postgrad Med 100(3):311-22 [PubMed]
- Stulberg (2002) Am Fam Physician 66(1):119-24 [PubMed]