Skip to Main Content

For further information, see CMDT Part 6-25: Impetigo

Key Features

Essentials of Diagnosis

  • Superficial blisters filled with purulent material that rupture easily

  • Crusted superficial erosions

  • Positive Gram stain and bacterial culture

General Considerations

  • A contagious and autoinoculable infection of the skin caused by staphylococci or rarely streptococci

  • In temperate climates, most cases are associated with Staphylococcus aureus infection

  • Streptococcus species are more common in tropical climates

Clinical Findings

Symptoms and Signs

  • The lesions consist of macules, vesicles, bullae, pustules, and honey-colored gummy crusts that when removed leave denuded red areas

  • The face and other exposed parts are most often affected

  • Ecthyma is a deeper form of impetigo caused by staphylococci or streptococci, with ulceration and scarring; it occurs frequently on the extremities

Differential Diagnosis

  • Contact dermatitis (acute)

  • Herpex simplex

Diagnosis

  • Gram stain and culture confirm the diagnosis

Treatment

  • Soaks and scrubbing can be beneficial, especially in unroofing lakes of pus under thick crusts

  • Topical agents such as bacitracin 500 units/g applied twice daily, mupirocin 2% ointment applied three times daily, or retapamulin 1% ointment applied twice daily can be attempted for 5–14 days for infections limited to small areas

  • Cephalexin, 250 mg four times daily orally

  • Doxycycline, 100 mg twice daily orally, or trimethoprim-sulfamethoxazole, double-strength twice daily orally, can be used for penicillin allergy and methicillin-resistant S aureus

  • Recurrent impetigo, which is due to nasal carriage of S aureus, is treated with rifampin, 300 mg orally twice daily, or mupirocin intranasal ointment applied intranasally twice daily for 5 days

  • Bleach baths (1/4 to 1/2 cup per 20 L of bathwater for 15 minutes 3–5 times weekly) for all family members may help reduce the spread

Outcome

Prevention

  • Individuals should not share towels if there is a case of impetigo in the household

Reference

+
Hartman-Adams  H  et al. Impetigo: diagnosis and treatment. Am Fam Physician. 2014 Aug 15;90(4):229–35.
[PubMed: 25250996]  

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.