Allergic skin reactions to exposure to environmental substances cause inflammation known as contact dermatitis which can result in weeks of blisters and itching. These rashes may be temporarily alleviated with medication, but permanent relief requires avoidance of the underlying allergen. Finding the culprit can often be achieved through taking a careful history of recent chemical exposures. Non-invasive patch testing of the skin is also an option for identifying the trigger allergen. Treatment with anti-allergy topical and oral medications helps alleviate and limit suffering.