Diseases Beginning with I

Disease & Vaccine A–Z

Diseases beginning with I

U.S.-focused summaries with current official guidance links. For a diagnosis, personal vaccine schedule, pregnancy advice, or urgent symptoms, speak with a qualified clinician.

Impetigo

No vaccine available

Disease

A contagious, superficial bacterial skin infection that is most common in young children but can affect anyone.

Symptoms

Small red bumps or blisters develop into pustules and then thick, golden or honey-colored crusts. Sores most often occur on the face, arms, or legs and may itch or feel mildly sore.

Typical duration

The incubation period for group A strep impetigo is about 10 days. With treatment, spread is reduced quickly and the skin usually heals over days to a few weeks.

How serious is it?

Most cases are limited to the skin, but infection can spread or rarely be followed by kidney inflammation. Rapidly expanding redness, fever, severe pain, swelling, or illness needs prompt medical assessment.

Treatment & management

A small number of lesions is often treated with a topical antibiotic; multiple lesions may require an oral antibiotic. The medicine should cover both group A strep and Staphylococcus aureus as directed by a clinician.

Vaccine: who and when?

No vaccine is currently available to prevent impetigo or group A strep infection in the United States.

Check the current CDC guidance for Impetigo →

Cost and access: Patient cost varies by insurance, provider, location, and eligibility. Many recommended vaccines are covered with no out-of-pocket cost under qualifying plans, and eligible children may receive vaccines through the Vaccines for Children program. CDC price lists are purchasing benchmarks—not guaranteed patient prices. CDC price and program context.

Last reviewed against official U.S. sources: September 5, 2026. This page provides general education, not medical advice.