Please describe things that are similar to contact dermatitis?

Irritant: Sometimes it is difficult to tell apart whether a rash , especially on the hands, is from an irritant or a contact allergens. Both them usually itch and may even be associated with small blisters. A skin patch test often can tell these apart.

Crusty rashes: Infected eczema, impetigo, pemphigus, and shingles bear some resemblance. An experienced physician or other health care professional you identify the rash. The picture is of poison oak-triggered contact dermatitis.

Skin Irritants: A list of the top culprits that trigger skin reactions, or contact dermatitis. Some cause symptoms like redness, itchy skin, or inflammation.Some are triggered by an individual's allergy (contact allergic dermatitis) while other chemicals affect everyone (contact irritant dermatitis). http://www.webmd.com/skin-problems-and-treatments/features/dirty-dozen#1