What Is Impetigo?

Impetigo is a highly contagious bacterial skin infection marked by the presence of red sores or blisters that rupture, ooze fluid, and form a yellowish, honey-colored crust. It typically occurs when bacteria penetrate the skin through a minor injury, such as a cut, scrape, or insect bite.

This skin condition is particularly common among children aged 2 to 5, but anyone can get it. It spreads easily, especially in crowded environments like schools, daycare centers, and contact sports. Though it’s often not serious, timely treatment is essential to prevent complications and reduce transmission.

Main Types of Impetigo

There are three primary forms of impetigo, each differing in presentation, cause, and severity.

Non-Bullous Impetigo

This is the most frequently observed type, accounting for about 70% of all impetigo cases. It’s caused by either Streptococcus pyogenes or Staphylococcus aureus. The infection often begins as small red sores that rapidly evolve into pus-filled blisters. These blisters rupture easily and form the characteristic yellow-brown crust.

Lesions are often localized and do not involve the deeper layers of the skin. They typically appear on the face—especially around the nose and mouth—but can occur anywhere the skin is broken.

Bullous Impetigo

This form is caused exclusively by certain strains of Staphylococcus aureus that produce toxins capable of creating larger, fluid-filled blisters. These blisters are often painless but can be fragile and burst easily.

Bullous impetigo usually appears on the trunk, arms, buttocks, and occasionally the face. Since it may affect deeper skin layers than the non-bullous type, healing can take longer, and treatment may require oral antibiotics.

Ecthyma

Ecthyma is a more severe variant that penetrates deeply into the skin. It develops when impetigo is left untreated or inadequately treated. This type results in painful ulcers with thick crusts and red, inflamed borders. It often affects the lower legs, buttocks, and thighs.

Unlike the other two types, ecthyma can leave permanent scars and may take weeks to resolve even with proper treatment.

Common Symptoms

Impetigo usually starts with red or pink sores, often itchy or slightly painful, that quickly develop into blisters. These blisters rupture and ooze fluid, eventually forming a distinctive crust.

Other potential symptoms include:

  • Itching and discomfort

  • Redness and swelling around the sores

  • Blisters that burst and expose raw skin

  • Fever or general malaise (in some cases)

  • Swollen lymph nodes near the affected area

Most cases appear on the face—around the nose and mouth—but the hands, arms, and legs can also be affected.

How It Spreads

Impetigo spreads primarily through direct contact with infected sores, contaminated surfaces, or through nasal secretions from someone who carries the bacteria.

Common transmission routes include:

  • Scratching an infected area and touching another part of the body

  • Skin-to-skin contact (handshakes, hugs, etc.)

  • Sharing personal items like towels, razors, or clothing

  • Using shared facilities or equipment in schools, gyms, or locker rooms

Because it’s so contagious, outbreaks can happen quickly in places with close contact, such as homes, schools, and childcare facilities.

Causes and Risk Factors

Impetigo is caused by two bacteria: Staphylococcus aureus and Streptococcus pyogenes. These organisms are common and typically harmless on healthy skin but become problematic when entering through minor skin damage.

Several factors increase your likelihood of developing impetigo:

  • Young age (especially 2–6 years)

  • Living in warm, humid environments

  • Poor hygiene or sanitation

  • Skin conditions like eczema or psoriasis

  • Participation in contact sports

  • Crowded or communal living environments

People with weakened immune systems are also more susceptible to infections, including impetigo.

Diagnosis

In most cases, healthcare professionals can diagnose impetigo simply by examining the affected skin. However, further tests may be recommended in certain situations—such as when the infection recurs, is severe, or doesn’t respond to standard treatment.

Diagnostic tools may include:

  • Skin swab: Fluid is collected from a sore and sent to the lab to identify the bacteria.

  • Nasal swab: Sometimes used in cases of repeated impetigo to check for bacterial colonization in the nose.

  • Skin biopsy: Rarely needed, but may be used when other skin conditions are suspected or when sores are atypical.

Effective Treatments

Prompt treatment of impetigo is essential to reduce symptoms, prevent spreading, and avoid complications. Most cases respond well to antibiotics—either topical or oral—depending on the severity.

Topical Antibiotics

For mild and localized infections, your healthcare provider may prescribe an antibiotic cream or ointment like:

  • Mupirocin (Centany)

  • Fusidic acid (Fucidin)

Apply it directly to the affected area 2–3 times a day, after gently cleaning the skin.

Oral Antibiotics

For widespread, severe, or bullous impetigo, oral antibiotics may be prescribed, such as:

  • Cephalosporins

  • Macrolides

Complete the entire course of antibiotics as prescribed, even if symptoms improve before finishing the medication.

At-Home Relief

While antibiotics address the root cause, several supportive measures can ease discomfort:

  • Warm compresses: Apply for 15–20 minutes to reduce itching and inflammation.

  • Gentle cleansing: Use antibacterial soap and a clean cloth to wash the area daily.

  • Cover the sores: Bandaging can help prevent spreading and reduce the urge to scratch.

  • Avoid scratching: Keep nails trimmed and clean. Consider gloves for children during sleep.

Preventive Measures

Since impetigo is so contagious, prevention is crucial—especially in communal settings. Practicing good hygiene and taking precautions can significantly reduce the risk of infection.

Key prevention tips include:

  • Frequent hand washing with soap and water

  • Avoid touching sores, especially before washing hands

  • Cover any open wounds or insect bites with clean bandages

  • Do not share towels, razors, bedding, or clothing

  • Regular bathing, especially after sports or outdoor activity

  • Disinfect commonly touched surfaces and equipment

  • Treat underlying skin conditions that make the skin more vulnerable

Children with impetigo should stay home from school or daycare until no longer contagious—typically 24 hours after beginning antibiotics.

Possible Complications

Most cases of impetigo resolve without long-term effects. However, untreated or severe infections can lead to complications:

Scarring

If the infection penetrates deeply or if sores are picked or scratched, scarring can result. Ecthyma is especially prone to leaving behind marks.

Cellulitis

In some cases, the infection spreads deeper into the skin, causing cellulitis—a serious condition characterized by redness, warmth, swelling, and pain.

Post-Streptococcal Glomerulonephritis (PSGN)

A rare but serious complication involving inflammation of the kidneys. It typically occurs after streptococcal infections and may present with:

  • Swelling in the face, hands, or legs

  • Dark or reddish urine

  • Decreased urine output

  • High blood pressure

  • Fatigue

Living With and Recovering from Impetigo

Impetigo is usually a temporary condition that clears with appropriate treatment in about one to two weeks. However, during recovery, managing discomfort and preventing reinfection are key.

To help ease symptoms:

  • Apply prescribed medication as directed

  • Take warm baths or use warm compresses

  • Wrap affected areas to discourage scratching

  • Maintain strict hygiene to avoid spreading the infection

If symptoms worsen or don’t improve after a few days of treatment, follow up with your healthcare provider. They may adjust your treatment or investigate underlying issues.

When to See a Doctor

Contact a medical professional if:

  • Sores spread rapidly or become more painful

  • You develop a fever or swollen lymph nodes

  • Sores are not improving after 48 hours of antibiotics

  • You notice signs of complications, such as fatigue or reduced urination

Final Thoughts

Impetigo, though usually mild, should not be underestimated due to its contagious nature and potential complications. Recognizing symptoms early and seeking timely treatment ensures a smooth recovery and helps protect others from infection.

By practicing good hygiene, managing skin injuries properly, and treating any underlying skin conditions, you can significantly reduce your risk of developing or spreading impetigo.