Contact Dermatitis

Contact dermatitis is an inflammatory process in skin caused by an exogenous agent or agents that directly or indirectly injure the skin. This injury may be caused by an inherent characteristic of a compound—irritant contact dermatitis (ICD). An example of ICD would be dermatitis induced by a concentrated acid or base. Agents that cause allergic contact dermatitis (ACD) induce an antigen-specific immune response (poison ivy dermatitis). The clinical lesions of contact dermatitis may be acute (wet and edematous) or chronic (dry, thickened, and scaly), depending on the persistence of the insult
Following types of contact dermatitis is commonly seen in routine practice
Irritant contact dermatitis
Allergic contact dermatitis

Treatment:

If contact dermatitis is suspected and an offending agent is identified and removed, the eruption will resolve. Usually, treatment with high-potency topical glucocorticoids is enough to relieve symptoms while the dermatitis runs its course. For those patients who require systemic therapy, daily oral prednisone beginning at 1 mg/kg, but usually 60 mg/d, is sufficient.
Identification of a contact allergen can be a difficult and time-consuming task. Patients with dermatitis unresponsive to conventional therapy or with an unusual and patterned distribution should be suspected of having ACD. They should be questioned carefully regarding occupational exposures and topical medications. Common sensitizers include preservatives in topical preparations, nickel sulfate, potassium dichromate, thimerosal, neomycin sulfate, fragrances, formaldehyde, and rubber-curing agents. Patch testing is helpful in identifying these agents but should not be attempted on patients with widespread active dermatitis or on those taking systemic glucocorticoids.