Hickory tussock caterpillar is perfectly innocent looking with tufts of white fuzzy hair and a interesting black pattern along its back. It is commonly seen between June and September feeding on the leaves of deciduous trees.
Though not lethal, the toxins present in the caterpillar’s hair can cause allergic reaction in some people. These hairs are also microscopically barbed and might lead to serious problems if transferred from the hands to the eye.
The toxins present on the caterpillar’s hair are part of its chemical defense that it acquires from its host plant.
If you are unfortunate enough to come into contact with the caterpillar, it is recommended to wash the area thoroughly as soon as possible and to anti-pruritic (anti-itching) lotion such as calamine.
The allergic symptoms commonly include burning, itching, reddening and rashes. The area must be immediately washed with soap and water, and applying ammonia or calamine lotion would help. However, those with hyperactive immune system might experience much severe symptoms like nausea and swelling and it’s better to see a physician in such cases.
[sources: wikipedia, oxfordcounty.ca, snopes.com]