Caterpillars likely to cause rashes, respiratory problems
June 25, 2012
VILSECK, Germany -- News agencies in Germany are reporting that 10 of Germany's 16 states are battling a population explosion of the Oak Processionary Caterpillar, and their toxic hairs can cause severe allergic reactions for some people.
Adverse reactions may occur when someone comes in direct contact with the hairs or inhales a hair that is floating in the air.
"If you touch those caterpillars, the hairs can break off and they are barbed, so they can stick into your skin," said Lt. Col. Mark Carder, Grafenwoehr Health Clinic commander and an entomologist. "There is a chemical associated with that hair that causes the skin to become irritated. We call them urticating hairs. If you were to inhale one of them, it could cause an allergic reaction."
Allergic reactions can be mild to very severe, which would require a person to see a health care provider, Carder said. Other symptoms include eye irritations and occasional respiratory symptoms.
Most symptoms are going to start out as an itchy rash and can be resolved with an over-the-counter medication, he said.
"If you feel like you have been in an area where the Oak Processionary Caterpillar lives or you have actually seen some, one of the first things you might want to do is change your clothes," Carder said.
Carder also recommends that people wash their clothes and take a shower to rinse off the hair if they believe they encountered the caterpillars.
Populations of the caterpillars will be the greatest when there is a warm and dry spring or summer.
"If the environmental conditions are just right, then you are going to have larger numbers," he said. "It is only those fourth through sixth larval caterpillar stages that cause a problem. That stage is pretty distinctly bound May through June.
However, the exposure risk isn't gone from the environment. The caterpillars form a community to start the lifecycle over again.
"There is always protection in numbers," Carder said. "They conglomerate together. Once they are in that web, it is almost like a community cocoon."
The hairs from the caterpillars can continue to cause a problem for people, Carder said.
"It takes pretty specific equipment to reduce the infestation," he said. "What you don't want to do is try and tear it down with a stick or something like that because… you will break those little hairs off. They will float around in the wind and you have the likelihood to inhale them and have some sort of allergic reaction."
If people see a web near an oak, Carder encourages people to stay away from the area and to call the Directorate of Public Works to remove the nest. A team from DPW will spray down the web with a bonding agent to keep the hairs from flying from the nest.
"If you see that in an oak tree, stay out of that area," Carder said. "It is best to not play or picnic under those types of trees. It is best to call DPW.
The Oak Processionary Caterpillar more than just a health risk, Carder said. Other risks to the environment are associated with the caterpillars.
"It can be pretty devastating to the oak tree," he said. "If caterpillars eat all the lefts off the tree, the trees can't make any energy to live."