Impetigo is a common, highly contagious bacterial skin infection that predominantly affects the superficial layers of the skin. Characterized by sores or blisters, it spreads easily through close contact. The duration of impetigo is directly tied to whether or not treatment is administered. This article focuses on the typical timelines for recovery and contagion, clarifying what to expect with and without medical intervention.
What Is Impetigo and Who Gets It?
Impetigo is a superficial infection most commonly caused by Staphylococcus aureus or Streptococcus pyogenes bacteria. These bacteria typically enter the body through a break in the skin, such as a minor cut, an insect bite, or an area affected by conditions like eczema. The infection is often called “school sores” due to its highly contagious nature in crowded environments.
While it affects people of all ages, impetigo is most common in infants and young children, particularly those between two and five. There are two main presentations. Non-bullous impetigo is the most frequent form, resulting in honey-colored crusts. Bullous impetigo is characterized by larger, fluid-filled blisters.
The Typical Timeline of Impetigo Recovery
The duration of impetigo is significantly altered by the use of antibiotics, which are recommended to speed up healing and prevent transmission. When treatment is started, either with a topical cream or oral medication, the infection typically begins to clear rapidly. A noticeable improvement in the lesions often occurs within 24 to 48 hours of starting the prescribed treatment.
With Antibiotic Treatment
With consistent antibiotic use, mild cases of impetigo usually resolve completely within seven to ten days. It is important to complete the entire course of medication as prescribed, even if the lesions appear to be gone sooner. Stopping treatment prematurely can lead to a recurrence of the infection or the development of antibiotic-resistant bacteria.
Without Treatment
Without treatment, impetigo takes a much longer time to resolve, often clearing on its own within two to three weeks, and sometimes up to four weeks. During this prolonged period, the sores can continue to spread to other parts of the body, and the risk of developing complications is increased. Untreated impetigo can, in rare instances, progress to ecthyma, a deeper skin infection that may result in scarring.
The physical healing process involves the lesions evolving from blisters or sores into dried, yellowish-brown crusts. Once the crusts fall off, the skin underneath is often a red or pink mark that gradually fades. Impetigo lesions usually heal without leaving permanent scars, unless the more severe ecthyma form develops or there is excessive scratching.
Why Healing Times Can Vary
Several factors influence whether an impetigo infection resolves quickly or takes a longer time to heal.
- Type of Impetigo: The bullous form, characterized by larger blisters, may take longer to clear than the more common non-bullous form.
- Severity and Extent: Larger, more widespread infections may require oral antibiotics instead of topical creams, which can alter the timeline.
- Antibiotic Adherence: Failure to use the medication for the entire duration means the bacteria may not be fully eliminated, leading to a relapse or prolonged healing.
- Underlying Skin Conditions: Conditions like atopic dermatitis or eczema compromise the skin barrier, making it more difficult for the body to fight the infection and potentially extending recovery time.
When Impetigo Is No Longer Contagious
The timeline for when impetigo ceases to be contagious is separate from the time it takes for the sores to fully disappear. For those receiving treatment, the infection is typically no longer considered contagious after 24 hours of starting the antibiotic medication. This 24-hour mark is the standard guideline for allowing individuals, particularly children, to return to school or daycare. Covering the remaining sores with a bandage or clothing is often recommended to further minimize transmission.
If a person chooses not to pursue antibiotic treatment, the contagious period lasts much longer. The infection remains transmissible until all the lesions have fully dried out and crusted over, and no new sores have appeared. This natural resolution can take up to two or three weeks, which is why treatment is strongly advised to limit the spread of the infection.