Home » ARTICLES » The Dr. is In » Two Timely Topics
Two Timely Topics PDF Print E-mail

Pertussis and Poison Oak

First, some news about pertussis (whooping cough). The State Health Department is reporting an epidemic of pertussis this year in California. There have been 5 infant deaths in the state (as of late June). Make sure your children are up-to-date with their shots. The “P” in the DTaP vaccine is for pertussis. In addition, kids should get a booster dose (“Tdap”) after age 11-12 years of age. All adults should also get the Tdap immunization, particularly women in the 3rd trimester of pregnancy and new moms. This is important because teens and adults are a “reservoir” for the pertussis bacteria and often spread it to young children in the home. Remember, whooping cough is most serious for young infants. Any cough lasting for more than 2 weeks is suspicious for pertussis.

Topic # 2 is poison oak. One wag remarked that there are only two kinds of people; those who get poison oak, and those who will get poison oak. This plant, whose leaves resemble an oak tree’s, produces an oil – urushiol – which is responsible for causing the allergic reaction we’re all familiar with. The oil is absorbed within minutes directly through the skin and chemically binds with deeper skin tissues. It is this bound urushiol which stimulates the immune reaction resulting in dermatitis. The rash is usually patchy and red, often with small blisters (vesicles), scratch marks, and may be oozy. There may be linear streaks, where the individual brushed up against the plant. Plant oil may also contact skin indirectly, from contaminated clothing or pet fur where the oil may persist for many days. Like any other allergy, individuals require several exposures over time before developing an allergic response. This response tends to worsen with repeated exposures during childhood, then generally lessens during adulthood. Treatment consists of showering within 30 minutes of exposure; but since the oil is so thick – like tree sap or pitch – it’s debatable whether using soap helps or merely spreads the oil out more on the skin. Rubbing (isopropyl) alcohol or Tecnu can help remove the oil if the exposed area is small. (Interestingly, Tecnu was developed during the cold war to remove radioactive dust from skin in case of nuclear war! In the past, many products, some really ridiculous, like kerosene, buttermilk, and even gunpowder have been tried for poison oak). Contaminated clothes should obviously be handled carefully and laundered. In mild cases, topical OTC creams or lotions may help reduce itchiness and inflammation; oatmeal or baking soda baths can be soothing. Antihistamines like diphenhydramine (generic for Benadryl) or Atarax (less sedating than Benadryl) are a good idea to increase comfort and reduce scratching behavior. A prescription steroid cream – like 0.1% TAC - is usually very effective. If the involved skin area is extensive, usual treatment is with oral prednisone for 1-2 weeks. This is really the only way to go if the rash is more severe.

Other factoids: dermatologists do not recommend using topical OTC’s containing dyphenhydramine (Benadryl) or benzocaine. Zanfel and IvyBlock are 2 OTC’s may be used preventatively. Familiarize yourself and your family with poison oak’s appearance; there are lots of pix on the internet. Remember that the leaves turn yellow or red in the fall. And if you burn leaves during fall pruning season, make sure to not burn p. oak; inhaling the smoke can cause some gnarly respiratory problems. Remember: “leaves of three, beware of me”!

Healthy Kidz Doc is written by a board-certified pediatrician who's practiced in Santa Cruz County since 1986. www.healthykidzdoc.yourmd.com


© Copyright 2008 all rights reserved