Tussock caterpillars (Erabidae family / previously Lymantriidae) were very abundant in Maine in 2011 and they were ‘itching’ for attention! One reason for all the attention they receive (during late summer and early fall) is that, unfortunately, the hairs on these caterpillars can cause a very itchy rash. The prickly hairs are a defense mechanism (they are not poisonous or venomous). It is important to note that children are more susceptible to the rash than are adults, and children are also much more likely to be playing with them and handling these showy critters (natural curiosity/fascination/playing outdoors). The rash from some of the members of this group tends to be short-lived, and clears up on its own after two or three hours. For other species, however, such as the Hickory Tussock (white one shown below), the rash can be much more severe and long-lasting, and a doctor’s visit might be warranted to speed one’s recovery and ease the symptoms / discomfort.
see also: Bangor Daily News story (August 30th, 2011)