Causes and Diagnoses

Causes and Diagnoses of Contact Dermatitis

The cause of contact dermatitis is an allergic reaction to an irritant or allergen that’s found in the environment. Common causes of contact dermatitis include:

• Soaps and detergent
• Saliva, especially pet saliva
• Foods
• Plants, including poison ivy
• Perfumes and fragrances
• Latex
• Lotion
• Cosmetics
• Hair dye
• Clothing dye
• Sunscreen
• Certain antibiotic creams
• Preservatives
• Solvents
• Agricultural products, such as fertilizers and pesticides
• Nickel in jewelry and on clothing (snaps, zippers, buttons)
• Chrome
• Mercury
• Airborne substances, such as pollen and aerosol sprays

Diagnosing contact dermatitis

Your physician can likely diagnose contact dermatitis during a physical exam and discussion of your symptoms. In rare cases, a biopsy (tissue sample) or scraping can be taken for analysis in a lab. Your physician may also recommend a patch test to determine the cause of the allergic reaction.