NEW ORLEANS - Because pediatricians are often faced with pediatric infectious disease emergencies, it is important to recognize life-threatening situations, said Russell W. Steele, MD, Children's Hospital, New Orleans.
Steele recently talked about the importance of pediatricians' ability to organize critical management steps in the diagnosis and treatment of serious infectious processes. He also stressed the issue of selecting appropriate antimicrobial agents based on likely pathogens known to cause life-threatening infections.
Steele is professor and vice chairman of pediatrics and division head of infectious diseases and immunology at Louisiana State University Medical School.
World's Deadliest Infections
|Infectious disease||Annual deaths|
|Acute respiratory infections
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Streptococcal toxic shock syndrome and necrotizing fasciitis, otherwise known as flesh-eating bacteria, are caused by group A b-hemolytic streptococci - specifically the pyogenic exotoxin A, which has greater virulence than other distinct types of streptococci, Steele said.
Although streptococcus cellulitis has always been a common secondary infection with varicella, the concern surrounds the new strain of streptococcus now circulating
"This is simply the mechanism in which these organisms get into the human body. In children, during chickenpox is the most common time that we see this secondary infection," he said. "Chickenpox hasn't increased, nor has the incidence of streptococcal infection, but the strain that causes [toxic shock] has increased."
Treatment for this illness also has changed, Steele said. Penicillin was previously the drug of choice, but clindamycin is now the preferred treatment. Penicillin no longer is effective because of the Eagle effect, which is a change in penicillin-binding proteins on the organisms in tissue. This was identified by Harry Eagle, MD, in the late 1950s.
"The penicillin can't attach to the organisms because of the new nature of the organism," he explained.
In addition, this disease is caused by a toxin in which the organism grows slowly; penicillin works best during the logarithmic phase of growth. Clindamycin is effective because it inhibits protein synthesis.
Ceftriaxone (Rocephin, Roche) is also an effective treatment, but more data are available on the use of clindamycin. "However, both offer benefits over penicillin," he said.
Pediatricians must be aware that streptococcal toxic shock syndrome and necrotizing fasciitis may appear as myositis, shock, renal impairment or respiratory distress. While all these should be considered in the differential diagnosis, it's possible those symptoms could be masking the true illness.
Degree of toxicity of sepsis can be defined by the Yale Observation Scale, which involves taking a feeding history, noting reaction to environment, irritability, consolability, social smile, quality of cry, color and hydration. However, the quantitative Yale Observation Scale, is not widely used by pediatricians, Steele noted.
The antibiotic treatment for sepsis depends on the age of the child. A child younger than 3 months should be given ampicillin plus gentamicin. A third-generation cephalosporin plus ampicillin is an additional option.
For children older than 3 months of age, only a third-generation cephalosporin is prescribed - unless pneumococcus is a likely pathogen. If so, Steele said vancomycin should be added to the regimen, as would be true for a child younger than 3 months.
"With true sepsis, vancomycin would be added to a third-generation cephalosporin," he said.
Monitoring should be conducted for development of multiple organ system failure including: arterial blood pressure, accurate hourly recording of fluid balance, neurological checks to assess level of consciousness and frequent arterial blood gas determination and observation for signs of respiratory distress. Determination of white blood cell and platelet counts, hematocrit and liver and renal function tests may also be desirable on a daily basis during the acute phase of illness.
Most commonly included in the differential diagnosis for botulism are Guillain-Barré syndrome, myasthenia gravis and sepsis. However, constipation is the most common symptom of botulism, followed by a weakness of antigravity muscles. A weak, high-pitched cry and decreased sucking are other common symptoms.
"A physician should consider botulism in the differential and do appropriate testing. It's not that subtle and a diagnosis should be made - and made relatively early," Steele said.
Supportive care is the only option for this illness because antibiotics are not effective and should not be given. Aminoglycosides only potentiate the neuromuscular blockade; the botulism toxin prevents repolarization and aminoglycosides simply enhances this process.
"By adding those [aminoglycosides] in, you have two blockers and it's much more severe," Steele said. "The babies should do well if properly diagnosed and treated."
Steele also said honey should be not be given to children younger than 1 year. Botulinal spores are present in approximately 13% of the honey on supermarket shelves.
Ehrlichiosis can occur anywhere in the United States and among all ages, but more cases are reported from the southeastern region of the country than anywhere else. Because the illness is similar to Rocky Mountain spotted fever, Steele recommends testing antibody levels to confirm the diagnosis.
"We're just beginning to understand how common it may be because the diagnosis is relatively difficult," he said. "It initially presents with flu-like symptoms, so a lot of things look like flu."
Tetracycline is the drug of choice; chloramphenacol was previously used often, but it is not as effective as tetracycline. Therefore, tetracycline is now the recommended treatment for all cases.
For more information:
- Steele RW. Common infectious diseases. Presented at the American Academy of Pediatrics annual meeting. New Orleans, Nov. 1-5.
- Steele RW. The Clinical Handbook of Pediatric Infectious Diseases. 1994. New York. Parthenon Publishing.
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