JOURNAL CLUB

Commentaries By Michael G. Burke, MD

DEET judged the most effective mosquito repellent

Deaths this summer in Louisiana resulting from West Nile virus infection lend new importance to a recent study that compares the efficacy of different repellents in protecting people from the bites of mosquitoes. Investigators tested the relative efficacy of 16 repellents, based on either synthetic chemicals or plant-derived essential oils. The repellents included seven botanicals (such as citronella); four products containing N,N-diethyl-m-toluamide, now called N, N-diethyl-3-methylbenzamide (DEET); a repellent with IR3535 (ethyl butylacetylaminopropionate); three repellent-impregnated wristbands; and Skin-So-Soft Original Bath Oil, the moisturizer that is commonly believed to have a repellent effect. The products were tested in a controlled laboratory environment using 15 volunteers.

DEET-based products provided complete protection for the longest time, and the higher the concentration, the longer the protection. When volunteers whose forearms were treated with a preparation containing 4.75% DEET thrust their arms into a cage of mosquitoes, the first bite occurred an average of 88.4 minutes later—compared with 301.5 minutes on an arm treated with 23.8% DEET. A controlled-release DEET formulation did not prolong the product's duration of action.

No non-DEET product protected for longer than 1.5 hours. Only the soybean oil–based repellent protected for nearly as long (88.4 minutes) as the lowest-concentration DEET product tested. Protection time for the IR3535–based repellent was, on average, 22.9 minutes; for citronella-based repellents, 20 minutes or less. Skin-So-Soft Original Bath Oil provided only 9.6 minutes of protection. With repellent-impregnated wristbands, which contained either 9.5% DEET or 25% citronella, protection time was, on average, only 12 to 18 seconds—not long enough to run back into the house for a repellent that contains DEET (Fradin MS et al: N Engl J Med 2002;347:13).

Commentary: So much for my stockpile of Skin-So-Soft. DEET-containing products appear to be the way to go. In an April 1998 report, the Environmental Protection Agency (EPA) concluded that "as long as consumers follow label directions and take proper precautions, insect repellents containing DEET do not present a health concern. . . ." For more on this subject, visit the EPA's Web site ( www.epa.gov/pesticides ).

Which AOM patients benefit from an immediate antibiotic?

In a randomized trial set in primary care practices, investigators determined the predictors of outcome in acute otitis media and assessed whether these predictors identify children who are likely to benefit from an immediate antibiotic. The 315 subjects, all of whom had an acute earache and otoscopic evidence of acute inflammation, were 6 months to 10 years old. Each received either an immediate antibiotic (amoxicillin or, for those allergic to penicillin, erythromycin) or a delayed antibiotic. Physicians asked parents whose children were in the delayed treatment group to wait 72 hours before considering using the prescription. The physicians recorded days of illness, physical signs, and filled antibiotic prescriptions, and parents kept a daily diary of their child's symptoms, perceived severity of pain, episodes of distress, temperature, vomiting, and other parameters of illness.

Analysis of the data showed that children who had a high temperature or experienced vomiting at the time of diagnosis were most likely to have a poor outcome by Day 3 of their illness. An immediate antibiotic in these children resulted in less distress, fewer disturbed nights, and fewer days of crying. Children who did not have a higher temperature or experience vomiting on the first day of illness benefited less from an immediate antibiotic.

Investigators concluded that clinicians should target for an immediate antibiotic the minority of children with systemic features (high temperature or vomiting), who are at higher risk of a poor outcome. Although cough also predicted poor outcome, it did not predict benefit from an antibiotic. The authors noted that, even among untreated children with systemic features, approximately half will feel better within 72 hours (Little P et al: BMJ 2002;325:22).

Commentary: We've always known that some children with otitis media heal spontaneously—but which ones? These authors hope to provide that answer. If their findings hold, the rate of antibiotic use may well continue to fall.

Physicians are prescribing fewer antibiotics for children

Investigators analyzed National Ambulatory Medical Care Survey data from 1989 through 2000 to assess the trend in prescribing of antimicrobials for children and adolescents younger than 15 years. Extracted data were for 1) antibiotic prescribing overall and 2) antibiotic prescribing for respiratory tract infection specifically. Two types of prescribing rates were used: a population-based rate (prescriptions for every 1,000 US children annually) and a visit-based rate (prescriptions every 1,000 patient visits). The number of US office-based physicians participating in each two-year period of the study ranged from 2,500 to 3,500.

The average population-based annual rate of overall antimicrobial prescribing decreased 40% from the 1989–1990 period to the 1999–2000 period (from 833 to 503 scripts for every 1,000 children annually). For patients given a diagnosis of respiratory tract infection, the average annual rate decreased 44% between these two periods.

The average visit-based annual rate of overall antimicrobial prescribing also decreased between the periods, but by less—29% (from 330 to 234 antibiotic prescriptions for every 1,000 children's visits). For respiratory tract infection, the visit-based decline was 14%. The decline in the population- and visit-based antimicrobial prescribing rates was similar for three of five specific respiratory tract infections analyzed: pharyngitis, sinusitis, and upper respiratory tract infection. For otitis media and bronchitis, however, a decrease was seen only in the population-based antimicrobial prescribing rate. This indicates that, for patients who made an office visit for otitis and bronchitis, physicians prescribed an antibiotic at the same rate they did 10 years ago (McCaig LF et al: JAMA 2002;287:3096).

Commentary: If these rate changes are accurate and not the result of reporting bias, they are the product of a huge effort: the education of physicians and the education of parents by physicians. It remains to be seen if the resistant bacterial strains will retreat in the face of this restraint.

Also of note

SSRI therapy associated with growth attenuation. A new report describes four children, all between 11 and 13 years old, who were treated with selective serotonin reuptake inhibitors for obsessive-compulsive disorder or Tourette syndrome. All had growth attenuation, possibly secondary to suppression of growth hormone secretion (Weintrob N et al: Arch Pediatr Adolesc Med 2002;156:696).

DR. BURKE, section editor for Journal Club, is chairman of the department of pediatrics at Saint Agnes Hospital, Baltimore. He is a contributing editor for Contemporary Pediatrics.

CLINICAL TIP

Good news for adherence, cubed

Giving prescription medication to a toddler is often difficult, so when I prescribe an antibiotic, I recommend that the parent make several different flavors of gelatin dessert and place them in a compartmentalized ice tray in the refrigerator (not the freezer) to gel. Then I give the parent a sample syringe, minus the needle. When it's time for a dose, the parent asks the child to choose which flavored gelatin cube "gets the medicine," removes the selected cube from the tray, and injects the medicine onto—not into—the cube. Once the cube is popped into the child's mouth, slipperiness and the tangy flavor do the rest.

Ruby R. Tan, MD
Skowhegan, Maine

A surprising use for an adhesive bandage

When dust, eyelashes, dirt, or other nonpenetrating foreign bodies get into the eye, a small adhesive bandage can be used to remove them. Unwrap a fresh bandage and lightly touch the foreign body with a corner or folded back portion of the adhesive strip. If you need to, you can even do it to yourself while looking in a mirror. Be sure to carefully lift the foreign body away from the cornea to avoid abrasion.

Dhiraj Ahlawat, MD
Ghaziabad, India

Do you have a Clinical Tip to share with colleagues? Let us know; we'll pay $50 for each item accepted for publication. Tips sent by mail should be addressed to Molly Frederick, Clinical Tips Editor, Contemporary Pediatrics, 5 Paragon Drive, Montvale, NJ 07645-1742. If you submit by e-mail (Molly.Frederick@medec.com), please include your mailing address.

Journal Club. Contemporary Pediatrics 2002;9:22.