Allergic Contact Dermatitis is a skin condition that occurs when the skin comes into contact with a substance that triggers an allergic reaction. Common allergens include poison ivy, nickel, and certain fragrances. Symptoms often include redness, itching, and swelling in the affected area. The condition develops after the immune system mistakenly identifies a harmless substance as a threat. Upon first exposure, the skin may not react, but subsequent contact can lead to a rash. Treatment typically involves avoiding the allergen and using topical corticosteroids to reduce inflammation and discomfort.