Dermatitis is caused by inflammation of the skin triggered by various factors, mainly exposure to irritants or allergens. There are two primary causes:
- Irritant Contact Dermatitis: This occurs when the skin's outer protective layer is directly damaged by irritants such as soaps, detergents, solvents, bleach, hair products, certain plants, fertilizers, or prolonged exposure to water. It may happen after a single strong exposure or repeated mild exposures over time.
- Allergic Contact Dermatitis: This is an immune reaction triggered by contact with allergens to which a person has become sensitized after repeated exposure. Common allergens include nickel in jewelry, cosmetic ingredients, medications (like antibiotic creams), preservatives, plants like poison ivy, and some sunscreens.
Other types of dermatitis, such as atopic dermatitis (eczema), can be related to genetic factors, weak skin barriers, allergies, or immune dysfunction. Additional factors influencing dermatitis include dry skin, infections, stress, and certain health conditions. Occupational exposure to irritants or allergens also increases risk. In summary, dermatitis results from skin irritation or allergic reaction to specific substances, leading to inflammation, redness, itching, and rash.
