- Contact Dermatitis (that spot on my ankle where a mean plant scratched me) - Contact is the act of touching, from the Latin contactus. Dermatitis is Greek - derma- means hide or skin, -itis means disease.
- Atopic Dermatitis (the rest of my legs, my arms) - Atopic is a Greekish word coined in 1923 by an American professor that means in an unusual place.
- Eczema - Mostly same thing as dermatitis. Also Greek, meaning "out of a boil."
- Hives - The common English word of unknown origin.
- Urticaria - from the Latin word for burn, is scientistspeak for hives. (Yes, I know there is a technical difference between uricaria and dermatitis, but an itch is still an itch.)
Oh, and we itch. God, do we itch. Nobody knows why. The scratch reflex probably is left over from billions of years ago when our rodent ancestors were trying to kill body lice. Scratching initially releases some feel good chemicals, the body's way of saying thank you. Then comes the why-the-hell-did-you-do-that rebound to punish us for scratching.