Anaphylaxis to polyvinylpyrrolidone after vaginal application of povidone-iodine

A 59-year-old woman who had had several episodes of contact urticaria after hair treatment, developed anaphylaxis after vaginal application of povidone-iodine solution for disinfection. Prick tests showed wheal-and-flare responses to both povidone-iodine (0.1% aqueous) and polyvinylpyrrolidone (povidone, PVP) (0.001% aq.), but not to iodine or polyoxy-ethyrenenonylphenyl ether, both of which are also contained in povidone-iodine solution. We confirmed that basophils from her peripheral blood released considerable amounts of histamine on stimulation by PVPs. It appeared that both the shampoo and the permanent-wave solution contained polyvinylpyrrolidone N, N-dimethyl aminoethyl methacrylic acid copolymer diethyl sulphate solution and polyvinylpyrrolidone styrene-copolymer emulsion. Both these agents in the hair care products provoked an immediate skin response on prick testing. We speculate that sensitization to PVP had been established by these hair care products at a beauty parlor. She was recommended to avoid PVP-containing products and remained free from symptoms thereafter.