An unusual complication of late onset allergic contact dermatitis to povidone iodine in oral & maxillofacial surgery - a report of 2 cases.

BACKGROUND Povidone iodine (PVP-I) is a chemical complex of polyvinylpyrrolidone (also known as povidone or PVP) and elemental iodine. Iodine containing compounds are widely and commonly used as antiseptics and disinfectants. They are available in various forms like aqueous solution, tincture, aerosol, ointment, or foam. Skin irritation to them is due to the oxidative effects of iodine. Because of the low free iodine concentration in povidone-iodine, skin irritation is less frequent from short contact (1). CASE We report two cases, both with no history of allergy to any drugs, who developed an allergic reaction 24 hours after the usage of povidone iodine as a pre-operative antiseptic to prepare (scrub) the lower third of face before surgical removal of third molars. This case report was granted an exemption by the ethical committee of our institution review board. The Helsinki declaration doesn't apply to this case presentation. CONCLUSIONS PVP-1 is the most commonly used antiseptic scrubbing solution prior to most surgeries. However, allergic contact dermatitis due to PVP-I has not been extensively documented or reported and hence under evaluated, compared to other commonly encountered allergens. There is almost general agreement to the proposition that PVP-I is a very rare sensitizer (2,3) though there are some conflicting reports on the matter. However, sometimes when prolonged skin contact with PVP-I occurs when used as a pre-operative antiseptic agent, it can cause allergic dermatitis (4,5). Does this finding make pre-operative testing for allergies to PVP-1 necessary in all patients? A point to ponder.