February 28, 2008 (New Orleans, Louisiana) — Results of a prospective, single-cohort, phase 2 study show safety and effectiveness for recanalization of the Penumbra System aspiration catheter in patients with acute stroke due to large vessel occlusion.
Results were presented here at the American Stroke Association International Stroke Conference 2008. The study was funded by Penumbra Inc, maker of the system, and designed by the company in collaboration with the Food and Drug Administration (FDA) to support an approval application; FDA approval for the aspiration device was received by the company in January 2008, when it was judged to be "substantially equivalent" to another currently approved mechanical device, the Concentric Balloon Guide Catheter (Concentric Medical Inc) for the indication of revascularization of patients with acute ischemic stroke secondary to large vessel occlusive disease within 8 hours of symptom onset.
"The device was able to achieve a higher-than-usual rate of recanalization (82%) with a low complication rate, with a range of intracerebral hemorrhages seen after stroke that are compatible with previous studies," said Cameron MacDougall, MD, chief of endovascular surgery at Barrow Neurological Institute, in Phoenix, Arizona, who presented the results here.
Phase 2 Study
The Penumbra System comprises a series of devices, primarily an aspiration catheter, with a distal wire to keep the catheter clear, and a grasping device designed to remove harder thrombus if the aspiration device fails to recanalize the vessel, Dr. MacDougall said.
In this phase 2 trial, 125 patients from 24 international centers with acute large vessel stroke were enrolled if they had failed treatment with intravenous tissue plasminogen activator (tPA) or were not candidates for treatment. Main entry criteria were an National Institutes of Health Stroke Scale (NIHSS) score of 8 or higher, presentation within 8 hours of symptom onset, and an occlusion (TIMI 0 or 1) of a treatable intracranial vessel.
Primary end points were revascularization of the target vessel, defined as TIMI 2 or 3 flow, and the incidence of procedural serious adverse events. Angiographic results were adjudicated by an independent core laboratory.
Mean age of the cohort was 64 years, with a baseline NIHSS score of 17.6 (range, 8 to 34), and a baseline modified Rankin Scale (mRS) of 4.5.
Revascularization of the target vessel was achieved in 82% of patients, all using the aspiration device only, Dr. MacDougall said. In fact, the grasping device was not approved because it was not effectively tested in enough patients in this study, he said.
There were 4 serious adverse events that were deemed to be procedure-related, but not device-related. Of these, 2 events occurred in the same patient; after failure of recanalization with the aspiration device, the investigator followed up with an angioplasty balloon that resulted in a perforation of the vessel and a subarachnoid hemorrhage and a parenchymal hemorrhage.
A third event, a parenchymal hemorrhage, occurred immediately after recanalization and was deemed a reperfusion hemorrhage that again was procedure- but not device-related. The fourth event was a small subarachnoid hemorrhage without hematoma that was felt to be a wire perforation, Dr. MacDougall said.
At 24 hours, intracranial hemorrhage (ICH) was seen in 35 patients (28%), 14 (11.2%) defined by computed tomography (CT) evidence of a bleed and deterioration of 4 points or more on the NIHSS. All-cause mortality was 26.4% at 30 days and 32.8% at 90 days.
Although the trial was not powered to look at clinical outcomes, the researchers reported that a favorable outcome at 30 days, defined as a 4-point improvement on the NIHSS at discharge or a 30-day mRS of 2 or less, was seen in 41.6% of patients. At 90 days, 25% of patients had an mRS of 2 or less. "The trend for a better outcome when vessels were opened was consistently seen across all neurological and functional measures," the authors write.
It is of note that Dr. MacDougall, while he presented the results here, was not the principal investigator for this trial; the trial actually did not have a principal investigator, a situation that he agreed was "odd."
"This was a company-sponsored, company-designed trial, in which the local principal investigators, including myself, did not control the design," he said. Instead, the design was defined through meetings of the company with the FDA, and end points were set comparing outcomes with the original Mechanical Embolus Removal in Cerebral Ischemia (MERCI) trial of the Merci retriever device.
Does Recanalization Equal Better Outcomes?
The approval of another device for revascularization of large vessels on the basis of recanalization in a single-cohort trial, rather than on improved clinical outcomes in controlled clinical trials, again raises the controversial issue of disparate approval processes by the FDA for drugs vs devices in the setting of stroke treatment.
Devices must be shown to be safe and to be effective in what they purport to do — in this setting, recanalizing the stroke-related vessel. Drug approval generally requires 2 studies showing safety and efficacy in phase 3 trials, comparing the drug with a control and looking at hard clinical outcomes.
"This is a prospective, phase 2 single-arm trial, so that's the beginning and end of the story," said Larry Goldstein, MD, from Duke University Medical Center, in Durham, North Carolina, who has written at length on this issue and was not involved in this trial. "The device can apparently remove clots. Whether that leads to better patient outcomes is not proven by this study," he told Medscape Neurology & Neurosurgery.
Although it would seem intuitive that an open vessel is better than a closed one, to date none of the approved devices have been shown in a randomized trial to actually improve outcomes. In the field of cardiology, for example, studies have begun to suggest that late revascularization of established clots may provide no ultimate benefit to the patient. At least 2 ongoing studies have incorporated mechanical clot removal in their trial design — the Interventional Management of Stroke Trial III (IMS III), and the Magnetic Resonance and Recanalization of Stroke Clots Using Embolectomy (MR-RESCUE). .
At a press conference here, Dr. MacDougall agreed there is an imperative for these types of devices, and this device in particular, to be tested in a randomized controlled trial powered to look at clinical outcomes. "That's what we care about, that the outcomes are better. Whether it's through the IMS III or some other mechanism, I think it's very important to get this into randomized trials where we can demonstrate that."
Although his involvement in the development of the Penumbra System is limited to this trial, he noted, "It's my understanding that plans are under way to move toward a mechanism for a randomized trial."
In the meantime, however, session moderator and American Stroke Association program committee chair Philip Gorelick, MD, from the University of Illinois College of Medicine, in Chicago, emphasized the importance of informed consent on this issue.
"Right now, it's exceedingly important that those who are potentially deploying the device have this very frank discussion with family and patients — if they are competent at the time of the stroke — so that they understand there is safety, that stroke is a bad disease that could lead to mortality, and there are potential risks here of using the device. But in terms of definitively showing [whether] the hard stroke outcomes in terms of stroke severity and poststroke function down the road will be improved, we don't really know."
The study was designed and funded by Penumbra Inc. Dr. MacDougall reports no financial disclosure relevant to this presentation.
American Stroke Association International Stroke Conference 2008: Abstract LB 4. Presented February 22, 2008.
Jumat, 29 Februari 2008
Makanan dan Susu Formula Bayi yang beredar di Indonesia Terkontaminasi Enterobacter sakazakii
Peneliti Fakultas Kedokteran Hewan Institut Pertanian Bogor (IPB) yang terdiri dari Dr. Sri Estuningsih, mengungkapkan sebanyak 22,73 persen susu formula (dari 22 sampel) dan 40 persen makanan bayi (dari 15 sampel) yang dipasarkan antara April - Juni 2006 telah terkontaminasi Enterobacter sakazakii. " Sampel makanan dan susu formula yang kami teliti berasal dari produk lokal," kata Estu. Menurut Estu, selain dirinya, beberapa staf pengajar Fakultas Kedokteran Hewan IPB yang bergabung dalam penelitian ini antara lain: Drh.Hernomoadi Huminto MVS, Dr. I.Wayan T. Wibawan, dan Dr. Rochman Naim.
Penelitian ini dilakukan melalui dua tahap. Tahap pertama, isolasi dan identifikasi E.sakazakii dalam 22 sampel susu formula dan 15 sampel makanan bayi. Tahap kedua, menguji 12 isolat E.sakazakii dari hasil isolasi dan kemampuannya menghasilkan enteroksin (racun) melalui uji sitolisis (penghancuran sel). Dari 12 isolat yang diujikan terdapat 6 isolat yang menghasilkan enteroksin. Uji selanjutnya adalah menguji isolat tersebut pada kemampuan toksinnya setelah dipanaskan. Terdapat 5 dari 6 isolat tersebut yang masih memiliki kemampuan sitolisis setelah dipanaskan.
Selanjutnya Estu menentukan satu kandidat dari isolat tersebut dan menguji enterotoksin serta bakteri vegetatifnya pada bayi mencit berusia enam hari. Bayi mencit diinfeksi melalui rute oral (cekok mulut) menggunakan sonde lambung khusus dan steril. Setelah 3 hari kemudian dilakukan pengambilan sampel organ mencit tersebut. "Hasil pengujian enteroksin murni dan enteroksin yang dipanaskan dan bakteri mengakibatkan enteritis (peradangan saluran pencernaan), sepsis (infeksi peredaran darah) dan meningitis (infeksi pada lapisan urat saraf tulang belakang dan otak). Pemeriksaan tersebut dilakukan dengan metode hispatologi menggunakan pewarnaan Hematoksilin Eosin.
Penelitian ini menyimpulkan di Indonesia terdapat susu formula dan makanan bayi yang terkontaminasi oleh E. Sakazakii yang menghasilkan enterotoksin tahan panas dan menyebabkan enteritis, sepsis dan meningitis pada bayi mencit. Dari hasil pengamatan histopatologis yang diperoleh masih dibutuhkan penelitian senada yang lebih mendalam untuk mendukung hasil penelitian tersebut. Sangat penting dipahami bahwa susu formula bayi bukanlah produk steril, sehingga dalam penggunaannya serta penyimpanannya perlu perhatian khusus untuk menghindari kejadian infeksi karena mengkonsumsi produk tersebut.
Estu secara pribadi telah menlihat langsung fasilitas salah satu perusahaan makanan dan susu formula dengan omzet terbesar di Indonesia. "Sebagian besar fasilitas tersebut telah memenuhi standar operasional prosedure perusahaan susu formula bayi, dan saat ini masih terus dilakukan upaya untuk mencegah kontaminasi tersebut," ujar Estu. (ris)
Penelitian ini dilakukan melalui dua tahap. Tahap pertama, isolasi dan identifikasi E.sakazakii dalam 22 sampel susu formula dan 15 sampel makanan bayi. Tahap kedua, menguji 12 isolat E.sakazakii dari hasil isolasi dan kemampuannya menghasilkan enteroksin (racun) melalui uji sitolisis (penghancuran sel). Dari 12 isolat yang diujikan terdapat 6 isolat yang menghasilkan enteroksin. Uji selanjutnya adalah menguji isolat tersebut pada kemampuan toksinnya setelah dipanaskan. Terdapat 5 dari 6 isolat tersebut yang masih memiliki kemampuan sitolisis setelah dipanaskan.
Selanjutnya Estu menentukan satu kandidat dari isolat tersebut dan menguji enterotoksin serta bakteri vegetatifnya pada bayi mencit berusia enam hari. Bayi mencit diinfeksi melalui rute oral (cekok mulut) menggunakan sonde lambung khusus dan steril. Setelah 3 hari kemudian dilakukan pengambilan sampel organ mencit tersebut. "Hasil pengujian enteroksin murni dan enteroksin yang dipanaskan dan bakteri mengakibatkan enteritis (peradangan saluran pencernaan), sepsis (infeksi peredaran darah) dan meningitis (infeksi pada lapisan urat saraf tulang belakang dan otak). Pemeriksaan tersebut dilakukan dengan metode hispatologi menggunakan pewarnaan Hematoksilin Eosin.
Penelitian ini menyimpulkan di Indonesia terdapat susu formula dan makanan bayi yang terkontaminasi oleh E. Sakazakii yang menghasilkan enterotoksin tahan panas dan menyebabkan enteritis, sepsis dan meningitis pada bayi mencit. Dari hasil pengamatan histopatologis yang diperoleh masih dibutuhkan penelitian senada yang lebih mendalam untuk mendukung hasil penelitian tersebut. Sangat penting dipahami bahwa susu formula bayi bukanlah produk steril, sehingga dalam penggunaannya serta penyimpanannya perlu perhatian khusus untuk menghindari kejadian infeksi karena mengkonsumsi produk tersebut.
Estu secara pribadi telah menlihat langsung fasilitas salah satu perusahaan makanan dan susu formula dengan omzet terbesar di Indonesia. "Sebagian besar fasilitas tersebut telah memenuhi standar operasional prosedure perusahaan susu formula bayi, dan saat ini masih terus dilakukan upaya untuk mencegah kontaminasi tersebut," ujar Estu. (ris)
Strategies for Diagnosis and Treatment of Impetigo
April 3, 2007 — Diagnosis and treatment strategies for impetigo are reviewed in the March 15 issue of American Family Physician.
"Impetigo is a highly contagious infection of the superficial epidermis that most often affects children two to five years of age, although it can occur in any age group," write Charles Cole, MD, and John Gazewood, MD, MSPH, from the University of Virginia School of Medicine in Charlottesville. "Among children, impetigo is the most common bacterial skin infection and the third most common skin disease overall, behind dermatitis and viral warts. Impetigo is more common in children receiving dialysis."
The authors searched Ovid Evidence-Based Medicine, the National Guideline Clearinghouse, the TRIP database, Clinical Evidence, and MEDLINE (1996 - 2005) and reviewed appropriate articles about impetigo.
There are 2 types of impetigo: nonbullous impetigo (impetigo contagiosa) and bullous impetigo. The former represents a host response to the infection, whereas the latter is caused by staphylococcal toxin, and no host response is required to manifest clinical illness.
Staphylococcus aureus is the most important causative organism; Streptococcus pyogenes (group A β-hemolytic streptococcus) causes fewer cases, either alone or combined with S aureus.
The diagnosis of impetigo usually is made clinically, but confirmation with Gram stain and culture may be helpful on occasion. Culture may help identify patients with nephritogenic strains of S pyogenes during outbreaks of poststreptococcal glomerulonephritis, or methicillin-resistant S aureus in suspected cases.
Nonbullous impetigo starts as a single red macule or papule that rapidly becomes a vesicle that ruptures easily to form an erosion. The vesicle contents dry to form characteristic honey-colored, often pruritic crusts. Autoinoculation often causes spread to surrounding areas. Nonbullous impetigo often affects the extremities, face, or other areas subject to trauma. If the infection is not treated, it usually resolves spontaneously without scarring in several weeks.
Impetiginous or secondary impetigo is a subtype of nonbullous impetigo that can complicate systemic diseases, such as diabetes mellitus and AIDS.
Bullous impetigo occurs most frequently in neonates but also can occur in older children and adults. This form of impetigo is a localized form of staphylococcal scalded skin syndrome caused by toxin-producing S aureus. Superficial vesicles rapidly develop into enlarging, flaccid bullae with sharp margins and no surrounding erythema. Yellow crusts with oozing occur when the bullae rupture. The "collarette" of scale surrounding the blister roof at the periphery of ruptured lesions is pathognomonic.
This form of impetigo typically develops at moist, intertriginous areas, such as the diaper area, axillae, and neck folds. Systemic symptoms are infrequent but can include weakness, fever, and diarrhea. Cases are usually sporadic and self limited, resolving in a few weeks without scarring.
Impetigo usually heals spontaneously within 2 weeks without scarring. However, treatment helps alleviate discomfort, improves cosmetic appearance, and prevents the spread of an organism linked to other illnesses, such as glomerulonephritis. In 5 placebo-controlled randomized trials, 7-day cure rates ranged from 0% to 42%.
Adults may have a higher risk for complications than children. Incidence of acute poststreptococcal glomerulonephritis is between 1% and 5% of patients with nonbullous impetigo, and the risk for this serious complication is not affected by treatment with antibiotics. Other rare potential complications include sepsis, osteomyelitis, arthritis, endocarditis, pneumonia, cellulitis, lymphangitis or lymphadenitis, guttate psoriasis, toxic shock syndrome, and staphylococcal scalded skin syndrome.
Despite the lack of standard treatment of impetigo, many options are available. The topical antibiotics mupirocin and fusidic acid are effective and may be superior to oral antibiotics, but the latter should be considered for patients with extensive disease. Topical disinfectants are not helpful to treat impetigo.
Although oral penicillin V is seldom effective, there is otherwise no clear preference among antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. However, resistance rates to erythromycin are rising.
Specific recommendations are as follows:
• For impetigo involving limited body surface area, topical antibiotics such as mupirocin and fusidic acid (not available in the United States) are the preferred first-line therapy (level of evidence, A).
• Oral antibiotics that are effective for treatment of impetigo are antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. Erythromycin is less effective (level of evidence, A).
• For patients with more extensive impetigo or disease associated with systemic symptoms, oral antibiotics should be considered (level of evidence, C).
• Oral penicillin V, amoxicillin, topical bacitracin, and neomycin are not recommended for the treatment of impetigo (level of evidence, B).
• Topical disinfectants such as hydrogen peroxide should not be used in the treatment of impetigo (level of evidence, B).
"Treatments ideally should be effective, inexpensive, and have limited side effects," the authors conclude. "Topical antibiotics have the advantage of being applied only where needed, which minimizes systemic side effects. However, some topical antibiotics may cause skin sensitization in susceptible persons."
Clinical Context
Impetigo, a highly contagious infection of the superficial epidermis, typically affects children aged 2 to 5 years, but it can affect people of all ages. It is the most common bacterial skin infection in children and the third most common skin disease overall. Nonbullous impetigo (impetigo contagiosa) represents a host response to the infection, whereas bullous impetigo is caused by staphylococcal toxin. S aureus is the most important causative organism; S pyogenes (group A β-hemolytic streptococcus) is responsible for fewer cases.
Impetigo is usually diagnosed clinically and can be confirmed by Gram stain and culture, but this is seldom necessary. Although impetigo usually heals spontaneously within 2 weeks without scarring, treatment helps to relieve discomfort, improve cosmetic appearance, and prevent the spread of staphylococcal infections. Despite the lack of standard treatment of impetigo, many options are available and effective.
Study Highlights
• The reviewers searched Ovid Evidence-Based Medicine, the National Guideline Clearinghouse, the TRIP database, Clinical Evidence, and MEDLINE (1996 - 2005) for articles about impetigo.
• Impetigo is usually transmitted through direct contact and often spreads rapidly through schools and daycare centers. After excoriating an infected area, patients can further spread the infection to themselves or others, and fomites also are important in the spread of impetigo. The incidence is greatest in the summer months, especially in crowded living conditions or in areas with poor hygiene.
• In 1 UK study, annual incidence of impetigo was 2.8% in children 4 years or younger and 1.6% among children 5 to 15 years of age.
• Impetigo is usually diagnosed clinically and is occasionally confirmed with Gram stain and culture, which can help identify patients with nephritogenic strains of S pyogenes or methicillin-resistant S aureus.
• In nonbullous impetigo, a red macule or papule on the extremities, face, or other areas subject to trauma rapidly becomes a vesicle that ruptures to form an erosion. The vesicle contents dry to form characteristic honey-colored, often pruritic crusts.
• Impetiginous (secondary) impetigo is a type of nonbullous impetigo associated with systemic diseases, such as diabetes mellitus and AIDS. Insect bites, varicella, herpes simplex virus, and other conditions disrupting skin integrity predispose patients to common impetigo.
• In bullous impetigo, superficial vesicles at moist, intertriginous areas rapidly develop into enlarging, flaccid bullae with sharp margins and no surrounding erythema. Yellow crusts with oozing occur when the bullae rupture. The "collarette" of scale surrounding the blister roof at the periphery of ruptured lesions is pathognomonic. This form of impetigo, which is seen most often in neonates but also can occur in older children and adults, is a localized form of staphylococcal scalded skin syndrome caused by toxin-producing S aureus.
• For impetigo involving limited body surface area, topical antibiotics such as mupirocin and fusidic acid (not available in the United States) are effective and are the preferred first-line therapy. Topical antibiotics are applied only where needed, thereby minimizing systemic adverse effects, but they may cause skin sensitization in susceptible persons.
• Topical disinfectants are not helpful to treat impetigo, and topical bacitracin and neomycin are not recommended.
• For patients with more extensive impetigo or disease associated with systemic symptoms, oral antibiotics should be considered. Although oral penicillin V or amoxicillin are seldom effective, there is otherwise no clear preference among antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. However, resistance rates to erythromycin are rising, thus making it less effective.
• Without treatment, most cases of impetigo resolve spontaneously in 2 weeks without treatment. In 5 placebo-controlled randomized trials, 7-day cure rates ranged from 0% to 42%.
• Adults may have a higher risk for complications than children. Incidence of acute poststreptococcal glomerulonephritis is between 1% and 5% of patients with nonbullous impetigo, and the risk for this serious complication is not affected by treatment with antibiotics. Other rare potential complications include sepsis, osteomyelitis, arthritis, endocarditis, pneumonia, cellulitis, lymphangitis or lymphadenitis, guttate psoriasis, toxic shock syndrome, and staphylococcal scalded skin syndrome.
"Impetigo is a highly contagious infection of the superficial epidermis that most often affects children two to five years of age, although it can occur in any age group," write Charles Cole, MD, and John Gazewood, MD, MSPH, from the University of Virginia School of Medicine in Charlottesville. "Among children, impetigo is the most common bacterial skin infection and the third most common skin disease overall, behind dermatitis and viral warts. Impetigo is more common in children receiving dialysis."
The authors searched Ovid Evidence-Based Medicine, the National Guideline Clearinghouse, the TRIP database, Clinical Evidence, and MEDLINE (1996 - 2005) and reviewed appropriate articles about impetigo.
There are 2 types of impetigo: nonbullous impetigo (impetigo contagiosa) and bullous impetigo. The former represents a host response to the infection, whereas the latter is caused by staphylococcal toxin, and no host response is required to manifest clinical illness.
Staphylococcus aureus is the most important causative organism; Streptococcus pyogenes (group A β-hemolytic streptococcus) causes fewer cases, either alone or combined with S aureus.
The diagnosis of impetigo usually is made clinically, but confirmation with Gram stain and culture may be helpful on occasion. Culture may help identify patients with nephritogenic strains of S pyogenes during outbreaks of poststreptococcal glomerulonephritis, or methicillin-resistant S aureus in suspected cases.
Nonbullous impetigo starts as a single red macule or papule that rapidly becomes a vesicle that ruptures easily to form an erosion. The vesicle contents dry to form characteristic honey-colored, often pruritic crusts. Autoinoculation often causes spread to surrounding areas. Nonbullous impetigo often affects the extremities, face, or other areas subject to trauma. If the infection is not treated, it usually resolves spontaneously without scarring in several weeks.
Impetiginous or secondary impetigo is a subtype of nonbullous impetigo that can complicate systemic diseases, such as diabetes mellitus and AIDS.
Bullous impetigo occurs most frequently in neonates but also can occur in older children and adults. This form of impetigo is a localized form of staphylococcal scalded skin syndrome caused by toxin-producing S aureus. Superficial vesicles rapidly develop into enlarging, flaccid bullae with sharp margins and no surrounding erythema. Yellow crusts with oozing occur when the bullae rupture. The "collarette" of scale surrounding the blister roof at the periphery of ruptured lesions is pathognomonic.
This form of impetigo typically develops at moist, intertriginous areas, such as the diaper area, axillae, and neck folds. Systemic symptoms are infrequent but can include weakness, fever, and diarrhea. Cases are usually sporadic and self limited, resolving in a few weeks without scarring.
Impetigo usually heals spontaneously within 2 weeks without scarring. However, treatment helps alleviate discomfort, improves cosmetic appearance, and prevents the spread of an organism linked to other illnesses, such as glomerulonephritis. In 5 placebo-controlled randomized trials, 7-day cure rates ranged from 0% to 42%.
Adults may have a higher risk for complications than children. Incidence of acute poststreptococcal glomerulonephritis is between 1% and 5% of patients with nonbullous impetigo, and the risk for this serious complication is not affected by treatment with antibiotics. Other rare potential complications include sepsis, osteomyelitis, arthritis, endocarditis, pneumonia, cellulitis, lymphangitis or lymphadenitis, guttate psoriasis, toxic shock syndrome, and staphylococcal scalded skin syndrome.
Despite the lack of standard treatment of impetigo, many options are available. The topical antibiotics mupirocin and fusidic acid are effective and may be superior to oral antibiotics, but the latter should be considered for patients with extensive disease. Topical disinfectants are not helpful to treat impetigo.
Although oral penicillin V is seldom effective, there is otherwise no clear preference among antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. However, resistance rates to erythromycin are rising.
Specific recommendations are as follows:
• For impetigo involving limited body surface area, topical antibiotics such as mupirocin and fusidic acid (not available in the United States) are the preferred first-line therapy (level of evidence, A).
• Oral antibiotics that are effective for treatment of impetigo are antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. Erythromycin is less effective (level of evidence, A).
• For patients with more extensive impetigo or disease associated with systemic symptoms, oral antibiotics should be considered (level of evidence, C).
• Oral penicillin V, amoxicillin, topical bacitracin, and neomycin are not recommended for the treatment of impetigo (level of evidence, B).
• Topical disinfectants such as hydrogen peroxide should not be used in the treatment of impetigo (level of evidence, B).
"Treatments ideally should be effective, inexpensive, and have limited side effects," the authors conclude. "Topical antibiotics have the advantage of being applied only where needed, which minimizes systemic side effects. However, some topical antibiotics may cause skin sensitization in susceptible persons."
Clinical Context
Impetigo, a highly contagious infection of the superficial epidermis, typically affects children aged 2 to 5 years, but it can affect people of all ages. It is the most common bacterial skin infection in children and the third most common skin disease overall. Nonbullous impetigo (impetigo contagiosa) represents a host response to the infection, whereas bullous impetigo is caused by staphylococcal toxin. S aureus is the most important causative organism; S pyogenes (group A β-hemolytic streptococcus) is responsible for fewer cases.
Impetigo is usually diagnosed clinically and can be confirmed by Gram stain and culture, but this is seldom necessary. Although impetigo usually heals spontaneously within 2 weeks without scarring, treatment helps to relieve discomfort, improve cosmetic appearance, and prevent the spread of staphylococcal infections. Despite the lack of standard treatment of impetigo, many options are available and effective.
Study Highlights
• The reviewers searched Ovid Evidence-Based Medicine, the National Guideline Clearinghouse, the TRIP database, Clinical Evidence, and MEDLINE (1996 - 2005) for articles about impetigo.
• Impetigo is usually transmitted through direct contact and often spreads rapidly through schools and daycare centers. After excoriating an infected area, patients can further spread the infection to themselves or others, and fomites also are important in the spread of impetigo. The incidence is greatest in the summer months, especially in crowded living conditions or in areas with poor hygiene.
• In 1 UK study, annual incidence of impetigo was 2.8% in children 4 years or younger and 1.6% among children 5 to 15 years of age.
• Impetigo is usually diagnosed clinically and is occasionally confirmed with Gram stain and culture, which can help identify patients with nephritogenic strains of S pyogenes or methicillin-resistant S aureus.
• In nonbullous impetigo, a red macule or papule on the extremities, face, or other areas subject to trauma rapidly becomes a vesicle that ruptures to form an erosion. The vesicle contents dry to form characteristic honey-colored, often pruritic crusts.
• Impetiginous (secondary) impetigo is a type of nonbullous impetigo associated with systemic diseases, such as diabetes mellitus and AIDS. Insect bites, varicella, herpes simplex virus, and other conditions disrupting skin integrity predispose patients to common impetigo.
• In bullous impetigo, superficial vesicles at moist, intertriginous areas rapidly develop into enlarging, flaccid bullae with sharp margins and no surrounding erythema. Yellow crusts with oozing occur when the bullae rupture. The "collarette" of scale surrounding the blister roof at the periphery of ruptured lesions is pathognomonic. This form of impetigo, which is seen most often in neonates but also can occur in older children and adults, is a localized form of staphylococcal scalded skin syndrome caused by toxin-producing S aureus.
• For impetigo involving limited body surface area, topical antibiotics such as mupirocin and fusidic acid (not available in the United States) are effective and are the preferred first-line therapy. Topical antibiotics are applied only where needed, thereby minimizing systemic adverse effects, but they may cause skin sensitization in susceptible persons.
• Topical disinfectants are not helpful to treat impetigo, and topical bacitracin and neomycin are not recommended.
• For patients with more extensive impetigo or disease associated with systemic symptoms, oral antibiotics should be considered. Although oral penicillin V or amoxicillin are seldom effective, there is otherwise no clear preference among antistaphylococcal penicillins, amoxicillin/clavulanate, cephalosporins, and macrolides. However, resistance rates to erythromycin are rising, thus making it less effective.
• Without treatment, most cases of impetigo resolve spontaneously in 2 weeks without treatment. In 5 placebo-controlled randomized trials, 7-day cure rates ranged from 0% to 42%.
• Adults may have a higher risk for complications than children. Incidence of acute poststreptococcal glomerulonephritis is between 1% and 5% of patients with nonbullous impetigo, and the risk for this serious complication is not affected by treatment with antibiotics. Other rare potential complications include sepsis, osteomyelitis, arthritis, endocarditis, pneumonia, cellulitis, lymphangitis or lymphadenitis, guttate psoriasis, toxic shock syndrome, and staphylococcal scalded skin syndrome.
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