Hand-washing is essential for preventing the spread of germs. But, sometimes, all this scrubbing can cause a rash. Does this mean you're allergic to the soap?

"One important thing to differentiate from allergic contact dermatitis is irritant contact dermatitis," says Mayo Clinic dermatologist Dawn Davis, M.D.

Dr. Davis says allergic dermatitis means a substance is causing an allergic reaction on your skin. But irritant contact dermatitis means your skin is inflamed from repeated exposure to something.

"For example, if I used lye soap on my skin, and I used it over and over again, I would develop an irritant contact dermatitis simply from eroding away the natural barrier of my skin with repetitive washing," says Dr. Davis.

Dr. Davis says it's not always easy to tell the difference between an allergy or irritant.

"So it's very helpful to go to a health provider, especially a dermatologist or allergist, to help differentiate between irritant contact dermatitis and an allergy," says Dr. Davis.

That way you can properly treat the rash and prevent it from happening again.