Allergen/irritant Distribution Poison ivy, oak, or sumac Linear plaques with vesicles and crusting “Black dot poison ivy” (see above) Lower abdomen (belt buckle, jean snaps); earlobe (earrings); preauricular and hands (cellphones) Around wounds and abrasions Eyelids Exposed surfaces including eyelids, face, upper chest, arms Widespread under clothing Widespread under clothing Groin region in contact with blue dye Nickel and cobalt Neomycin Nail polish (acrylates) Fragrances (airborne) Fragrances (in detergents) Dyes (in clothing) Disperse blue dye (in diapers) Car seat lining (irritant vs allergic) Mango peel Wet wipes (methylisothiazolinone) Cocamidopropyl betaine (soaps and shampoos) Lanolin (found in emollients) Botanicals (found in many organic emollients) Rubber and leather (e.g., shoes) Toilet seats (cleaning supplies) Sunscreens, fragrances (photoallergic contact Occipital scalp, extensor elbows, posterior thighs, posterior lower legs Perioral, hands Perianal, groin, and perioral Widespread Widespread Widespread Dorsal feet sparing, especially great toe May affect soles Posterior thighs May form ring including lateral and superior buttocks Photodistributed (face, chest, dorsal hands, and forearms)