Atopic dermatitis is due to a hypersensitivity reaction (similar to an allergy) in the skin, which leads to long-term swelling and redness (inflammation) of the skin. People with atopic dermititis may lack certain proteins in the skin, which leads to greater sensitivity.

Atopic dermatitis is most common in infants. It may start as early as age 2 to 6 months. Many people outgrow it by early adulthood.

People with atopic dermatitis often have asthma or seasonal allergies. There is often a family history of allergic conditions such as asthma, hay fever, or eczema. People with atopic dermatitis often test positive to allergy skin tests.

However, atopic dermatitis is not caused by allergies. The condition tends to get worse when the person is exposed to certain triggers.

The following can make atopic dermatitis symptoms worse:

• Allergies to pollen, mold, dust mites, or animals
• Cold and dry air in the winter
• Colds or the flu
• Contact with irritants and chemicals
• Contact with rough materials, such as wool
• Dry skin
• Emotions and stress
• Exposure to too much water, such as taking too many baths or showers and swimming too often
• Feeling too hot or too cold, as well as sudden temperature changes
• Fragrances or dyes added to skin lotions or soaps