High Yield Topics

Impetigo

By admin



Ovid: 5-Minute Sports Medicine Consult, The


Impetigo
Arturo J. Aguilar
Basics
Description
  • Superficial skin infection of the epidermis with Staphylococcus aureus or group A beta-hemolytic streptococcus or a combination of the 2, classically characterized as well-defined erythematous papules and pustules with honey-colored crust (1)
  • Divided into bullous and nonbullous types (1)
  • Bullous (2):
    • Caused by epidermolytic toxin from Staphylococcus aureus
    • Favors intertriginous areas
    • Is a localized form of scalded skin syndrome
    • Starts as a vesicular eruption that develops into bullae and then may rupture to form honey crusts
  • Nonbullous (more contagious) (2):
    • Caused by Staphylococcus aureus and group A beta-hemolytic streptococcus (GAS)
    • Starts as macules or papules and progresses to vesicular eruption, which rupture to form erosions with honey crusts
  • Impetiginous (or common) impetigo is a nonbullous subtype that is a complication of systemic diseases such as diabetes mellitus or HIV. It may also develop as a secondary infection of a cut, scrape, or insect bite (1).
  • May be transmitted person to person or person to athletic equipment by direct contact (1)
  • Can also be spread by autoinoculation from skin excoriations in contact with other parts of the body (1)
  • Synonym(s): Scrum strep (1)
Epidemiology
  • Most common bacterial skin infection in children (2)
  • 3rd most common skin infection overall (2)
  • Most common in areas of skin-to-skin contact between athletes (1)
  • Most common on face and upper extremities (1)
  • Incidence is greatest in the summer months (1)
  • 14.2% of skin infections in men's wrestling practices (3)
Risk Factors
  • Abrasions or open cuts allow passage of bacteria through the epidermis (1).
  • Sweat- and water-soaked clothes allow easy passage of bacteria through the 1st protective layer of the epidermis (stratum corneum) (1).
  • Poor hygiene (1,3)
General Prevention
Techniques (1):
  • Avoid sharing equipment, towels, tape, and ointments.
  • Avoid dispensing ointments from common containers.
  • Clean equipment and clothes daily.
  • Shower immediately after sports activity with antibacterial soap.
  • Shower before using communal hot tubs.
  • Wear moisture-wicking, synthetic clothing.
  • Discourage body shaving in contact sports.
  • Frequent skin checks by athletic trainers and athletes in contact sports
  • Frequent handwashing by athletic trainers and affected athletes
  • Cover any injured skin immediately.
  • Use topical triple antibiotic for skin wounds.
Etiology
  • Bullous (2):
    • Epidermolytic toxin from Staphylococcus aureus
  • Nonbullous (2):
    • Staphylococcus aureus and/or GAS
Diagnosis
History
  • Mild itching and soreness (1)
  • May be an infection of a minor skin injury or occur on unimpaired skin (1)
  • May have accompanying pharyngitis (2)
  • Bullous (1,2):
    • Starts with superficial vesicles, which progress to flaccid bullae without surrounding erythema
    • When the bullae rupture, they ooze and create honey-colored crusts.
    • Self-limited and may spontaneously resolve in weeks if left untreated
  • Nonbullous (more contagious) (1,2):
    • Starts as a single macule or papule that develops into a vesicle
    • Vesicle may rupture and form an erosion, and the contents become honey-colored crusts that are often pruritic.
    • May spontaneously resolve without scarring if left untreated for weeks
Physical Exam
Findings (1,2,4):
  • Clear vesicles in the early stages
  • Some may progress to pustules and/or bullae
  • When vesicles or pustules/bullae break, they will have a honey-colored crust with erythematous papules or erosions.
  • Lesions may range from millimeters up to several centimeters in diameter.
  • Mainly located on face and upper extremities
  • Regional lymphadenopathy
Diagnostic Tests & Interpretation
  • Diagnosis is based on history and clinical appearance (1).
  • Cultures can be done if history or epidemic of methicillin-resistant Staphylococcus aureus (MRSA)
Lab
  • Wound culture to confirm or rule out MRSA if recent epidemic on the athletic team (1)
  • Throat culture if symptoms of pharyngitis for GAS (2)

P.327


Differential Diagnosis
  • Acne vulgaris (1)
  • Folliculitis (2)
  • Poison ivy (2)
  • Atopic dermatitis (2)
  • Herpes gladiatorum (1)
  • Tinea corporis gladiatorum (1)
Treatment
Methods (1):
  • Soak affected skin in warm water for 5–10 min 3 times daily until cleared.
  • Manually remove honey-colored crusts to improve antibiotic penetration.
  • Wash area with povidone-iodine liquid soap.
Medication
First Line
  • Mild (1,4):
    • Topical 2% mupirocin twice a day for 10 days
    • Topical fusidic acid (not available in the U.S.)
    • Bacitracin/neomycin found to be less effective in a 2003 meta-analysis
  • Moderate or widespread (adult dosing) (1,4):
    • Topical therapy in combination with oral antibiotic coverage
    • Amoxicillin/clavulanate 250–500 mg 2 times a day for 10 days
    • Dicloxacillin 250–500 mg 3–4 times a day for 10 days
    • Cephalexin 250–500 mg 3–4 times a day for 10 days
    • Penicillin-allergic oral therapy (4):
      • Erythromycin
      • Clindamycin
  • MRSA-positive lesions (1):
    • Topical 2% mupirocin with trimethoprim/sulfamethoxazole or clindamycin for at least 14 days
Second Line
  • Tetracycline (4)
  • Vancomycin (4)
  • Linezolid (4)
  • Dactinomycin (4)
Additional Treatment
  • Clean clothes in bleach and water at a temperature of at least 71°C (1).
  • Clean equipment with diluted bleach solution (1).
Ongoing Care
Return-to-play guidelines (3):
  • College:
    • National Collegiate Athletic Association wrestling rules for competition:
      • Oral antibiotics for at least 72 hr prior to competition
      • No new lesions for 48 hr before a meet or tournament
      • No moist, exudative, or purulent lesions at the meet or tournament time
      • Active purulent lesions shall not be covered to allow participation
      • Firm adherent crusts may be covered with a nonpermeable dressing that will not dislodge.
  • High school:
    • Each state's high school association has varying guidelines for competition.
Follow-Up Recommendations
Patient Monitoring
Recurrent infection should be considered for evaluation and possible treatment for Staphylococcus aureus carrier state (2).
Patient Education
Educate athletes and athletic staff regarding the importance of good hygiene (3).
Prognosis
Untreated, may last several weeks to months but ultimately self-limiting (1).
Complications
Secondary (1,2,4):
  • Poststreptococcal glomerulonephritis up to 3 wks after skin infection:
    • Occurs in 20% of nonbullous-type impetigo
    • Risk not decreased with antibiotic treatment
  • Hyperpigmented area after healed lesions mostly in dark-skinned athletes
  • Cellulitis
  • Lymphangitis
  • Guttate psoriasis
  • Toxic shock syndrome
  • Staphylococcal scalded skin syndrome
  • Sepsis
  • Osteomyelitis
  • Pneumonia
References
1. Adams BB. Bacterial skin infections. Sports Dermatology. New York: Springer, 2006:3–8.
2. Habif PT. Bacterial infections. Clinical dermatology. Mosby, 2004:267–272.
3. National Collegiate Athletic Association. Skin infections in athletics. 2009–10 NCAA Sports Medicine Handbook. National Collegiate Athletic Association, 2009:56–63.
4. Cole C, Gazewood J. Diagnosis and treatment of impetigo. American Family Physician. 2007;75:859–864.
Codes
ICD9
684 Impetigo


Continue Reading
You might also like More from author

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More