Narrator: This is Science Today. As many allergy sufferers know all too well, between now and early winter, a variety of weeds and grasses will continue to release allergy-causing pollens. While many people believe these plants to be the prime culprits behind allergic reactions, trees can also share the blame. Dennis Pittenger, a horticulture expert at the University of California, Riverside, says trees can cause rashes or severe itching, either from touching them or inhaling their pollen. Pittenger describes some of the trees that cause these reactions.
Pittenger: Box elder - many of the alders, the white alder, the red alder in particular, birches can be allergenic to people. Oaks, many of the oaks, people have a problem with oaks, pines in some cases. Ash, particularly olive - many people are aware of that, but also sycamores and cottonwoods can cause problems, along with elms.
Narrator: If you suspect trees may be behind your allergic reactions and would like to pinpoint which ones, check with your doctor or an allergist for testing. For Science Today, I'm Larissa Branin.