Based on forensic evidence, we believe the invasion begin on the left foot, where the left index toe, henceforth referred to as "Typohoid Piggy," came into direct contact with the perpetrator. At that point, contact was somehow made between that toe and the first kunckle of the left thumb - an odd connection, but given the host's level of dexterity, the only possibility. From there, the true magnitude of this crime revealed itself. Acting as a carrier, the thumb distributed the offending toxin to the back of the neck, the right side of the neck, and most perversely, just to the side of each eye. Meanwhile, Typhoid Piggy, shared the toxin with its larger neighbor, who had just returned from the market. Calamine lotion was applied to all offending locations at this point, but the damage had already been done.
Explanation: Poison ivy sucks. That's my explanation. Actually, based on what I found in my backyard today, it may actually be poison sumac. Regardless, itching is no fun, and I look like an idiot with this Calamine* lotion on my face.
*Actually it's Kalamina, direct from Spain, circa 2005 - the last time I got poison-anything. I bought it here if you're interested.