Is Impetigo Contagious?

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: Melissa Conrad Stöppler, MD
    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD

    Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Impetigo Treatment

Impetigo is not serious and is very treatable. Mild impetigo can be handled by gentle cleansing, removing crusts, and applying the prescription-strength antibiotic ointment mupirocin (Bactroban). Nonprescription topical antibiotic ointments (such as Neosporin) generally are not effective.

What is impetigo? Causes

Impetigo (impetigo contagiosa) is a superficial bacterial infection most frequently observed in children 2-5 years of age, although adults may become infected. Lesions begin as papules (small bumps) and then progress to small vesicles (blisters) surrounded by redness of the skin (usually on the face near the mouth and on extremities). Vesicles become larger and leak fluid, producing a characteristic golden crust on the lesions.

There are two major types of impetigo: nonbullous (the most common type described above) and bullous impetigo, which is characterized by enlarged vesicles filled with a clear yellow fluid that becomes darkened and, when ruptured, forms a brownish crust. The patient's body (trunk) is often infected in contrast to nonbullous impetigo.

Unlike impetigo, ecthyma is a more serious infection that penetrates deeply into the skin; it produces fluid or pus-filled sores that are painful. These sores can produce ulcers in the skin. This subtype is not often seen.

Is impetigo contagious?

Impetigo is a highly contagious disease. Impetigo is easily spread from person to person by direct contact with the lesions and/or indirectly by touching items (clothing, sheets, or toys) that have been used by individuals with this skin disease. Indirect transmission is less frequent than direct person-to-person transmission. Bacteria cause impetigo; group A streptococci and staphylococci are the organisms that most frequently cause impetigo.

What does impetigo look like? What is the incubation period for impetigo?

A person infected with impetigo usually starts out with irritating, itchy blisters that can develop pus. The incubation period is about one to three days for streptococci and about four to 10 days for staphylococci. The individual may also develop local lymph node enlargement. Diagnosis of impetigo is often made clinically without special testing by the patient's history and physical examination and the appearance of the characteristic crusting lesions. However, the diagnosis can be confirmed by isolation and identification of the bacteria from the skin lesions.

Medically Reviewed by a Doctor on 11/7/2016

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