Irritant contact dermatitis
The irritants direct cytotoxic impact on epidermal keratinocytes causes Irritant contact dermatitis. This disrupts the skin barrier and activates the innate immune system. Keratinocytes in the epidermis can be actually affected by irritants. It is a complicated reaction that is influenced by genetic and environmental elements, both of which have a role in the pathogenesis of the disease. It can be seen in both occupational and non-occupational environments but its more common in the occupations dealing in low humidity conditions. Irritant contact dermatitis (ICD) can be divided into forms caused by chemical irritants, and those caused by physical irritants. Common chemical irritants implicated include: solvents (alcohol, xylene, turpentine, esters, acetone, ketones, and others); metalworking fluids (neat oils, water-based metalworking fluids with surfactants); latex; kerosene; ethylene oxide; surfactants in topical medications and cosmetics (sodium lauryl sulfate); and alkalis (drain cleaners, strong soap with lye residues). Physical irritant contact dermatitis may most commonly be caused by low humidity from air conditioning. Also, many plants directly irritate the skin. Allergic contact dermatitis
Allergic contact dermatitis (ACD) is accepted to be the most prevalent form of immunotoxicity found in humans, and is a common occupational and environmental health problem. By its allergic nature, this form of contact dermatitis is a hypersensitive reaction that is atypical within the population. The development of the disease occurs in two phases, which are induction and elicitation. The process of skin sensitization begins when a susceptible subject is exposed to the allergen in sufficient concentration to elicit the required cutaneous immune response.
It may be applied to the skin as a cream or ointment. If the reaction covers a relatively large portion of the skin or is severe, a corticosteroid in pill or injection form may be prescribed.In severe cases, a stronger medicine like halobetasol may be prescribed by a dermatologist. Antihistamines. Prescription antihistamines may be given if non-prescription strengths are inadequate. See also
Urushiol-induced contact dermatitis
Nickel allergy
Eczema

References
External links

eMedicine Health article on contact dermatitis