What sort of disease is contact dermatitis?

Allergy: A person can be allergic to may items in the enviornment, e.g., nickel in jewellary, chemicals in household items. Once a person is sensitized, exposure to the item causes inflammatio in the skin leading to itching, thickened skin, ulceration and oozing, i.e., eczema.

Poison ivy: The most commonly known contact dermatitis is the reaction some people develop to poison ivy/ poison oak. Many times you may contact the oils from these plants and even though it didn't cause problems before, you start itching 12-24 hours after touching the plant the blisters develop usually 2 days later. Your immune system is trying to kill any part of your skin that has plant oils on it.