Impetigo

Overview

Impetigo is a common and highly contagious skin infection that mainly affects infants and young children. It typically shows up as red sores on the face, especially around the nose and mouth, as well as on the hands and feet. Over about a week, these sores burst and develop honey-colored crusts.

There are a few different types of impetigo, including:

• Non-bullous umpetigo (early-stage):
  • Begins with the development of one or more itchy sores that quickly burst.
  • The skin around the sores becomes red or raw.
  • Swollen glands may appear near the sores.
  • Eventually, honey-colored crusts form over the sores, and the skin heals without scarring.
• Bullous impetigo (more common in infants):
  • Involves the formation of large, fluid-filled blisters on the child’s skin, with no redness around the surrounding skin.
  • These blisters later become clear and limp before breaking open.
  • Crusty sores then develop on the skin, and healing occurs without scarring.
• Ecthyma (A more serious type):
  • Ecthyma is a more severe form of impetigo that goes deeper into the skin.
  • It begins with painful blisters on the child’s skin that turn into deep, open sores.
  • Thick crusts develop on the skin, and redness often appears in the surrounding area.
  • After the skin heals, scars may form because the infection penetrated deeper into the skin.

Treatment with antibiotics can help prevent the spread of impetigo to others. Children should stay home from school or daycare until they are no longer contagious, which is usually about 24 hours after starting antibiotic treatment.

Symptoms

Impetigo is a contagious skin condition characterized by blisters, rashes, and various skin lesions that can contain pus and form a yellow or tan crust when they burst. Itching and soreness are usually mild. These skin issues can appear on the lips, nose, ears, arms, and legs, and can spread to other areas through touch, clothing, or towels. Symptoms typically appear about three days after the bacteria infect the skin.

• Bullous impetigo: This less common form involves the development of large fluid-filled blisters that eventually become clear and break open, leading to crusty sores. It typically heals without scarring.
• Ecthyma: A more severe form, ecthyma causes painful blisters that evolve into deep, open sores covered by thick crusts, often with redness in the surrounding area. It can potentially lead to scarring as it penetrates deeper layers of the skin.

Impetigo should be diagnosed and treated by a healthcare provider to prevent complications, although complications are rare. Left untreated, it can result in skin damage or scarring.

Causes

Impetigo is primarily caused by certain bacteria, with the most common culprits being Staphylococcus aureus (“staph”) responsible for 80% of non-bullous cases, and Group A streptococcus (“strep”) responsible for 10% of cases. These bacteria typically enter the skin through cuts, scrapes, rashes, or insect bites, leading to inflammation and infection.

Impetigo can also develop when a person scratches itchy skin conditions like chickenpox or eczema, breaking the skin and allowing bacteria to enter. Additionally, it can occur without prior skin damage, often associated with conditions like head lice, scabies, or eczema. In some cases, adults can contract impetigo due to health issues like tattoo infections.

Risk factors

Several factors can increase the risk of developing impetigo, which include:

• Age: Impetigo is most frequently seen in children aged 2 to 5 years.
• Skin damage: The bacteria responsible for impetigo often enter the skin through minor injuries like small cuts, insect bites, or existing rashes.
• Close contact: Impetigo is highly contagious and can easily spread within families, crowded environments like schools and childcare facilities, and through activities involving skin-to-skin contact, such as sports.
• Warm and humid weather: Impetigo infections tend to be more prevalent in regions with warm and humid weather conditions.
• Other underlying health conditions: Individuals with pre-existing skin conditions like atopic dermatitis (eczema) are at a higher risk of developing impetigo. Additionally, older adults, those with diabetes, or individuals with weakened immune systems are more susceptible to this skin infection.