impetigo n : a very contagious infection of the skin; common in children; localized redness develops into small blisters that gradually crust and erode

English

Noun

impetigo (plural impetigos)

1. A contagious bacterial skin disease forming pustules and yellow crusty sores, chiefly on the face and hands. It is common in children and infection is often through cuts or insect bites.

Derived terms

• impetigenous
• impetiginous

For the band, see Impetigo (band).

Impetigo (sometimes impetaigo) is a superficial bacterial skin infection most common among children 2 to 6 years old. People who play close contact sports such as rugby, American football and wrestling are also susceptible, regardless of age. The name derives from the Latin impetere ("assail"). It is also known as school sores.

Causes

Impetigo is usually caused primarily by Staphylococcus aureus, with frequent secondary infection by Streptococcus pyogenes. According to the American Academy of Family Physicians - "Nonbullous impetigo was previously thought to be a group A streptococcal process and bullous impetigo was primarily thought to be caused by S. aureus. Studies now indicate that both forms of impetigo are primarily caused by S. aureus with Streptococcus usually being involved in the nonbullous form"

Diagnosis

The diagnosis is made based on the typical appearance of the skin lesion.

Transmission

The infection is spread by direct contact with lesions or with nasal carriers. The incubation period is 1–3 days. Dried streptococci in the air are not infectious to intact skin. Scratching may spread the lesions.

Prevention

Good hygiene practices can help prevent impetigo from spreading. Those who are infected should use soap and water to clean their skin and take baths or showers regularly. Non-infected members of the household should pay special attention to areas of the skin that have been injured, such as cuts, scrapes, bug bites, areas of eczema, and rashes. These areas should be kept clean and covered to prevent infection. In addition, anyone with impetigo should cover the impetigo sores with gauze and tape. All members of the household should wash their hands thoroughly with soap on a regular basis. It is also a good idea for everyone to keep their fingernails cut short to make hand washing more effective. Contact with the infected person and his or her belongings should be avoided, and the infected person should use separate towels for bathing and hand washing. If necessary, paper towels can be used in place of cloth towels for hand drying. The infected person's bed linens, towels, and clothing should be separated from those of other family members, as well.

Impetigo contagiosa

Impetigo contagiosa has pimple-like lesions surrounded by reddened skin. Lesions fill with pus, then break down over 4–6 days and form a thick, honey-colored crust. Impetigo is often associated with insect bites, cuts, and other forms of trauma to the skin. Itching is common. People who suffer from cold sores have shown higher chances of suffering from impetigo. Those who normally suffer from cold sores should consult a doctor if normal treatment has no effect. Impetigo also causes flu-like symptoms which may cause fatigue, weakness of muscles, headaches and vomiting.

Bullous impetigo

Bullous impetigo primarily affects infants and children younger than 2 years. It causes painless, fluid-filled blisters — usually on the trunk, arms and legs. The skin around the blister is usually red and itchy but not sore. The blisters, which break and scab over with a yellow-colored crust, may be large or small, and may last longer than sores from other types of impetigo

Ecthyma

Ecthyma is a more serious form of impetigo in which the infection penetrates deeper into the skin's second layer, the dermis. Signs and symptoms include:

• Painful fluid- or pus-filled sores that turn into deep ulcers, usually on the legs and feet
• A hard, thick, gray-yellow crust covering the sores
• Swollen lymph glands in the affected area
• After crust disappears little holes the size of pinheads to the size of pennies appear after crust recedes
• Scars that remain after the ulcers heal

Treatment

For generations, the disease was treated with an application of gentian violet, an antifungal agent http://www.bmj.com/cgi/content/full/329/7472/979. Today, topical or oral antibiotics are usually prescribed. Treatment may involve washing with soap and water and letting the impetigo dry in the air. Many general practitioners choose to treat impetigo with bactericidal ointment, such as fusidic acid (Fucidin) or mupirocin (Bactroban), but in more severe cases oral antibiotics, such as flucloxacillin (e.g., Floxapen) or erythromycin (e.g., Erythrocin) or Dicloxacillin are necessary. Amoxicillin combined with clavulanate potassium may also be used as an antibiotic treatment

References

External links

• NIH/Medline
• Photo (University of Iowa)
• Dermnet NZ

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