Detergents, surfactants, extremes of pH, and organic solvents all directly affect the barrier properties of the epidermis.

Chemical irritants are often strong alkalis as found in drain cleaners and soap with lye residues.

A complete patient history combined with negative allergic patch testing is usually necessary to reach a correct diagnosis.

Low humidity from air conditioning was found to be the most common cause of physical irritant contact dermatitis.

[citation needed] Food handlers and kitchen workers often take precautions to wear rubber or latex gloves when peeling butternut and acorn squash to avoid temporary butternut squash (Cucurbita moschata) dermatitis[6] A contact dermatitis reaction to butternut or acorn squash may result in orange and cracked skin, a sensation of "tightness", "roughness" or "rawness".