An unusual complication of late onset allergic contact dermatitis to povidone-iodine in oral and maxillofacial surgery

Povidone-iodine (PVP-I) is a chemical complex of polyvinylpyrrolidone (also known as povidone or PVP) and elemental iodine. Compounds containing iodine are widely and commonly used as antiseptics and disinfectants. They are available in various forms, such as aqueous solution, tincture, aerosol, ointment or foam. Skin irritation 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 (Chambers, Basic and clinical pharmacology, 8th ed, 2001, p. 852).

This article reports two cases of patients both with no history of allergy to any drugs, who developed an allergic reaction 24 h after the usage of povidone-iodine as a preoperative antiseptic to prepare the lower third of face before surgical removal of third molars. This case report was granted an exemption by the ethical committee of the institution review board. The Helsinki declaration does not apply to this case presentation.

Povidone-iodine is the most commonly used antiseptic solution prior to surgery. However, allergic contact dermatitis due to PVP-I has not been extensively documented or reported and hence underevaluated compared to other commonly encountered allergens. There is almost general agreement to the proposition that PVP-I is a very rare sensitizer (Brandao et al., Textbook of contact dermatitis, 3rd ed, pp. 687–723, 2001; Marks et al., Contact and occupational dermatology, 3rd ed, 2002) although there have been some conflicting reports on the matter. However, sometimes when prolonged skin contact with PVP-I occurs when used as a preoperative antiseptic agent it can cause allergic dermatitis (Velázquez et al., Contact Dermat 60:348–349, 2009; Lachapelle et al., Contact Dermat 52:9–10, 2005). Does this finding make preoperative testing for allergies to PVP-1 necessary in all patients? A point to consider.