Calamine is a mixture of zinc oxide (ZnO) with about 0.5% ferric oxide (Fe2O3). It is the main ingredient in calamine lotion and is used as an antipruritic (anti-itching agent, attributed to the presence of phenol in the formulation) to treat mild pruritic conditions such as sunburn, eczema, rashes, poison ivy, chickenpox, and insect bites and stings.[1][2][3][4][5][6] It is also used as a mild antiseptic to prevent infections that can be caused by scratching the affected area, and an astringent to dry weeping or oozing blisters and acne abscesses.[7]
In a 1992 press release, the U.S. Food and Drug Administration announced that no proof had been submitted showing the main ingredients in calamine (zinc oxide and iron(III) oxide) to be safe for use or effective in treating bug bites, stings, and rashes from poison ivy, poison oak, and poison sumac.[8] The press release listed a total of 415 over the counter (OTC) drug ingredients which the FDA proposed banning for specific uses which are as yet unproven.
In a September 2, 2008, document, the U.S. Food and Drug Administration recommended applying topical OTC skin protectants, such as calamine, to relieve the itch caused by poisonous plants such as poison ivy, poison oak, and poison sumac.[9]