According to a 2009 study by the Green Patriot Working Group, the most allergenic brands of laundry detergent are Tide, Ivory Snow Gentle, Tide Free and Purex. These brands showed the highest concentration of a toxic chemical called 1,4-dioxane, which can cause allergic reactions.
The EPA cites 1,4-dioxane as a carcinogen that also disrupts the kidneys and neurological and respiratory systems.
WebMD lists symptoms of allergic reactions as redness, scaling, oozing blisters, itching and burning. Swelling, hives and sun sensitivity are some additional signs of an allergic reaction. In addition to laundry detergent, soap, dryer sheets, clothing and household cleaners top the list of skin irritants that can cause allergic reactions.