A condition whereby the sufferer does not like to be out in public or surrounded by people for long periods of time. The sufferer would rather be alone and by themselves than have interaction with other people. The person with this condition is not a loner, just someone who prefers their own company to the company of others.
"That's Shannon over there, she's got Hermititis. I think she caught it in Iowa."
"Hey Shannon, whats up with you today? You don't seem to be yourself.."
"Oh, thats just my Hermititis flaring up again. Must be a full moon."