Contact dermatitis is an inflammatory skin condition that can occur when the skin is exposed to an irritating or allergenic substance. For example, skin may become dry, red, and cracked after coming in contact with strong soaps, pesticides, or poison ivy. Depending on the cause and severity of symptoms, treatment may include avoiding the cause of the symptoms, taking medications, or using lubricants or other treatments.
Contact dermatitis is a type of eczema caused by exposure to substances in the environment. It is one of the two most common types of eczema (atopic dermatitis is the other). Contact dermatitis can affect anyone, regardless of age, gender, or ethnicity.
There are two types of contact dermatitis: irritant contact dermatitis and allergic contact dermatitis.
Irritant Contact Dermatitis
Irritant contact dermatitis is the more common type. It is a non-allergic inflammatory skin reaction caused by exposure to irritating substances that actually damage the skin. Not everyone develops allergies, but everybody's skin can become irritated if abused.
Contact with strong irritants, such as acid or lye, can result in blisters, erosion, and ulcers within minutes or hours. For weaker irritants, such as soaps or detergents, exposure over days or weeks may be necessary before the condition develops.
Any substance can act as an irritant (even water) if it is concentrated enough and if the skin is exposed to it long enough.
Allergic Contact Dermatitis
Allergic contact dermatitis results from the skin's reaction to a substance (allergen) to which it has become sensitized, or allergic. Normally, the skin doesn't react the first time it meets up with an allergen. Sometimes it occurs with the second exposure. But in other cases, it takes years and many exposures for hypersensitivity to a particular substance to develop. Once sensitized, the skin will usually become inflamed within hours or days after contact.