Impetigo disease

    What is impetigo?

    Impetigo (say "im-puh-TY-go") is a bacterial skin infection. It causes red sores that can break open, ooze fluid, and develop a yellow-brown crust. These sores can occur anywhere on the body.

Impetigo is one of the most common skin infections in children. It can occur in adults but is seen far more often in children. Impetigo is contagious and can be spread to others through close contact or by sharing towels, sheets, clothing, toys, or other items. Scratching can also spread the sores to other parts of the body.

What causes impetigo?

Impetigo is caused by one of two kinds of bacteria—strep (streptococcus) or staph (staphylococcus). Often these bacteria enter the body when the skin has already been irritated or injured because of other skin problems such aseczema, poison ivy, insect bites, burns, or cuts. Children may get impetigo after they have had a cold or allergies that have made the skin under the nose raw. But impetigo can also develop in completely healthy skin.

What are the symptoms?

You or your child may have impetigo if you have sores:

• That begin as small red spots, then change to blisters that eventually break open. The sores are typically not painful, but they may be itchy.
• That ooze fluid and look crusty.
• That increase in size and number. Sores may be as small as a pimple or larger than a coin.

How is impetigo diagnosed?

Your doctor can usually diagnose impetigo just by looking at your or your child's skin. Sometimes your doctor will gently remove a small piece of a sore to send to a lab to identify the bacteria. If you or your child has other signs of illness, your doctor may order blood or urine tests.

How is it treated?

Impetigo is treated with antibiotics. For cases of mild impetigo, a doctor will prescribe an antibiotic ointment or cream to put on the sores. For cases of more serious impetigo, a doctor may also prescribe antibiotic pills.

A child can usually return to school or daycare after 24 hours of treatment. If you apply the ointment or take the pills exactly as prescribed, most sores will be completely healed in 1 week.

At home, gently wash the sores with clean water each day. If crusts form, your doctor may advise you to soften or remove the crusts. You can do this by soaking them in warm water and patting them dry. This can help the cream or ointment work better.

After you touch the area, wash your hands with soap and water or use an alcohol-based hand sanitizer.

Try not to scratch the sores, because scratching can spread the infection to other parts of the body. You can help prevent scratching by keeping your child's fingernails short. You can cover the sores with a loose bandage. The sores need air to heal.

Call your doctor if you do not get better as expected or if you notice any signs that the infection is getting worse, such as fever, increased pain, swelling, warmth, redness, or pus.

How can impetigo be prevented?

If you know someone who has impetigo, try to avoid close contact with that person until his or her infection has gone away. Do not share towels, sheets, or clothes until the infection is gone. Wash anything that may have touched the infected area.

If you or your child has impetigo, scratching the sores can spread the infection to other areas of your body and to other people. Wash your or your child's hands with soap to help prevent spreading the infection.

TREATMENT 

Topical treatment for impetigo 

Fusidic acid 2% ointment†17

Apply to affected skin three times daily for seven to 12 days

Available in Canada and Europe

Mupirocin 2% cream (Bactroban)‡8,18

Apply to affected skin three times daily for seven to 10 days; reevaluate after three to five days if no clinical response

Approved for use in persons older than three months

15-g tube:

30-g tube:

Mupirocin 2% ointment

Apply to affected skin three times daily for seven to 14 days

Dosing in children is same as adults

Approved for use in persons older than two months

22-g tube:

Retapamulin 1% ointment (Altabax)

Apply to affected skin twice daily for five days

Total treatment area should not exceed 100 cm²in adults or 2% of total body surface area in children

Approved for use in persons nine months or older

15-g tube: NA ($130)

30-g tube: NA ($245)

NA = not available.

—Estimated retail price based on information obtained at http://www.goodrx.com (accessed April 7, 2014). Generic price listed first; brand listed in parentheses.

—Coverage for Staphylococcus aureus (methicillin-susceptible) and streptococcus.

—Coverage for S. aureus (methicillin-susceptible) and streptococcus. Mupirocin-resistant streptococcus has now been documented.^6,14

—First member of the pleuromutilin class of antibiotics. Coverage for S. aureus (methicillin-susceptible) and streptococcus.¹⁹

Information from references 6, 8, 11,14, and 17 through 19.

Retapamulin is a novel pleuromutilin antibacterial and the first new topical antibacterial in nearly 20 years.14Pleuromutilins, derived from the fungus Clitopilus passeckerianus, have antibacterial activity against gram-positive bacterial organisms.20Retapamulin acts on three key aspects of bacterial protein synthesis, making it far less likely to induce resistant strains. In 2007, the U.S. Food and Drug Administration approved retapamulin 1% ointment for the treatment of impetigo due to S. aureus (methicillin-susceptible isolates only) or S. pyogenes in adults and children at least nine months of age. Retapamulin is not approved for intranasal staphylococcal carrier treatment or treatment of MRSA-related skin infections.6,19  Pricing of the two topical treatment options available in the United States varies depending on preparation. Mupirocin is available as a less expensive generic version and as a brand. All available mupirocin products are less expensive than the newer brand-only retapamulin ointment (Table 2 6,8,11,14,17–19).

ORAL ANTIBIOTICS

Oral antibiotic therapy can be used for impetigo with large bullae or when topical therapy is impractical 

       Shown below 

ADULT SEVEN-DAY DOSE	COST (FOR A TYPICAL COURSE OF TREATMENT)*	CHILDREN SEVEN-DAY DOSE	COST*
Amoxicillin/clavulanate (Augmentin)†	875/125 mg every 12 hours	$19 ($193)	Younger than three months: 30 mg per kg per day Three months or older: 25 to 45 mg per kg per day for those weighing less than 40 kg (88 lb); 875/125 mg every 12 hours for those weighing 40 kg or more Based on mg per kg per day of the amoxicillin component in divided doses every 12 hours	1 bottle, 400/57 mg per 5 mL (100-mL oral suspension): $30 ($125)
Cephalexin (Keflex)	250 mg every six hours or 500 mg every 12 hours	$5 ($90)	25 to 50 mg per kg per day in divided doses every six to 12 hours	1 bottle, 250 mg per 5 mL (100-mL oral suspension): $14 (NA)
Clindamycin‡	300 to 600 mg every six to eight hours	$18 ($200)	10 to 25 mg per kg per day in divided doses every six to eight hours	1 bottle, 75 mg per 5 mL (100-mL oral solution): $47 (pricing varies by region)
Dicloxacillin	250 mg every six hours	$14 (NA)	12.5 to 25 mg per kg per day in divided doses every six hours	See adult pricing: no liquid formulation available
Doxycycline§	50 to 100 mg every 12 hours	$15 ($95)	2.2 to 4.4 mg per kg per day in divided doses every 12 hours Not recommend in children younger than eight years	1 bottle, 25 mg per 5 mL (60-mL oral suspension): $20 (pricing varies by region)
Minocycline (Minocin)§	100 mg every 12 hours	$36 ($185)	Loading dose of 4 mg per kg for first dose (maximum dose of 200 mg), then 4 mg per kg per day in divided doses every 12 hours Maximum of 400 mg per day Not recommend in children younger than eight years	See adult pricing: no liquid formulation available
Trimethoprim/sulfamethoxazole§	160/800 mg every 12 hours	$4 (NA)	8 to 10 mg per kg per day based on the trimethoprim component in divided doses every 12 hours	1 bottle, 40/200 mg per 5 mL (100-mL oral suspension): $4 (pricing varies by region)

---

note: Because of emerging resistance, penicillin and erythromycin are no longer recommended treatments.12

NA = not available.

*—Estimated retail price based on information obtained at http://www.goodrx.com (accessed April 7, 2014). Generic price listed first; brand listed in parentheses.

†—Good coverage forStaphylococcus aureus (methicillin-susceptible) and streptococcus.

‡—If methicillin-resistant S. aureus is suspected or proven.

§—If methicillin-resistant S. aureus is suspected or proven. There is no activity against streptococcus.

Information from references 12 and 15.

The incidence of MRSA-related skin and soft tissue infections was increasing, but more recent studies show it may be declining.21 No studies have specifically identified a problem with MRSA-related impetigo in adults or children, but cultures may still be useful in some settings.6,12 If MRSA infection is suspected, initial treatment with trimethoprim/sulfamethoxazole, clindamycin, or a tetracycline (doxycycline or minocycline [Minocin]) is recommended pending culture results.6 Although trimethoprim/sulfamethoxazole is effective for S. aureus infection, including most MRSA infections, its use for impetigo is limited by inadequate coverage of streptococcal bacteria. Oral clindamycin penetrates skin and skin structures and should be considered if MRSA infection is suspected. Because of an increasing risk of pseudomembranous colitis, clindamycin should be reserved for patients allergic to penicillin, or for infections that fail to respond to other treatments. Tetracyclines can be used for susceptible MRSA infections, but should be avoided in children younger than eight years.12 Oral fluoroquinolones are not preferred because of low staphylococcal activity and their potential association with tendinopathy and arthropathies.12

TOPICAL DISINFECTANTS

There are some studies on the benefits of nonantibiotic treatments, such as disinfectant soaps, but they lack statistical power.11 Disinfectants appear to be less effective than topical antibiotics and are not recommended.8Studies comparing hexachlorophene (not available in the United States) with bacitracin and hydrogen peroxide with topical fusidic acid found the topical antibiotic to be more effective.8,22,23

NATURAL THERAPIES

The evidence is insufficient to recommend or dismiss popular herbal treatments for impetigo.24 Natural remedies such as tea tree oil; tea effusions; olive, garlic, and coconut oils; and Manuka honey have been anecdotally successful. The fact that impetigo is self-limited means that many “cures” could appear to be helpful without being superior to placebo. In one study, tea leaf ointment and oral cephalexin (Keflex) were similarly effective, with a cure rate of 81% vs. 79%.25 Tea tree oil (derived from Melaleuca alternifolia) appeared to be equivalent to mupirocin 2% for topical decolonization of MRSA.26

Future Treatments

Jump to section +

Future treatments for impetigo might include minocycline foam (Foamix), which has successfully completed phase II trials, and Ozenoxacin, a topical quinolone that has successfully completed phase III clinical trials.27,28Few controlled clinical trials have had their results published and most are methodologically weak. This area seems to merit further study through rigorous clinical trials.

TOP