An exanthem is any eruptive skin rash that may be associated with fever or other systemic symptoms. Causes include infectious pathogens, medication reactions and, occasionally, a combination of both.

Contact dermatitis is a common cause of a rash in one area. This is especially true of a small rash that will not go away. Contact dermatitis usually starts as raised red spots. It can change to ...

You can only see it with a microscope. It gets into the skin of humans by mistake. The rash and itching are the body's allergic reaction to parasites in the skin. This parasite can be found in lakes ...

Skin biopsy: To do this, your dermatologist removes a small sample from your rash, so that it can be examined under a microscope. Nail biopsy: If lichen planus may be affecting one or more of your ...

The allergic reaction typically occurs one to two days after exposure. The reaction causes a rash that can continue to be seen for weeks after the allergen is removed. There are four hypersensitivity ...