Contact dermatitis, also known as “allergic contact dermatitis” and ” irritant contact dermatitis”, is a general term that describes an itchy rash caused when skin is exposed to an allergen or irritant.
Contact dermatitis is categorized in the eczema family and the most common form of contact dermatitis is poison ivy. In addition, many cases of hand eczema are caused by exposure to allergens and irritants and are classified as contact dermatitis.
Overview of Contact Dermatitis
A wide range of substances can trigger contact dermatitis, including:
- Plants such as poison ivy, poison oak and poison sumac
- Metals, particularly nickel and chromate found in earrings, watches, necklaces, buttons and belt buckles
- Chemicals such as solvents, detergents, alkalis and acids
- Fragrances found in lotions, shampoos, cosmetics and perfumes
- Latex and rubber found in gloves
- Over-the-counter topical medications including neomycin, bacitracin and hydrocortisone
- Other substances (preservatives in leather and clothing, hair dyes, nail polish additives, glues, etc.)
Environmental factors can also play a significant role in contact dermatitis. Sunlight can trigger an allergic reaction to some substances, and cold air and low humidity can exacerbate the reaction.
Occupational risks are numerous in industries involving cleaning, catering, metalwork, hairdressing, healthcare and mechanical work. Most contact dermatitis that is caused by work or aggravated by work affects the hands.
Reactions may be immediate or may take hours to appear, and can be mild to severe depending on the individual’s allergic sensitivity to the substance and the concentration of the exposure.
Upon exposure to an allergen or irritant, the skin may appear either red, swollen and blistered, or dry and bumpy. In severe cases, the rash can spread to areas beyond the point of exposure.
Treatment of Contact Dermatitis
It is important to pinpoint the cause of the reaction if it is not known. Your doctor will take steps to determine the cause of the reaction, including a review of exposures and allergy testing such as patch testing.
When the cause of the reaction is known, avoidance of the substance is necessary. Some allergens, such as hair dye chemicals and glue, can penetrate rubber gloves, so glove protection may not be effective.
Your doctor may prescribe a number of treatments including moisturizers, topical steroids, oral steroids and more advanced medications depending on the severity of the reaction.Treatment can take weeks or longer, and it is important to pay close attention to ingredients in common substances such as lotions to avoid hidden triggers.
Results of Treatment
Most contact dermatitis can be completely eradicated using the range of topical and oral medications available today.
More persistent, chronic cases can generally be controlled and minimized through extended treatment and careful avoidance to allergens and irritants.