Related Experiment Videos
Allergic contact dermatitis from iodine preparations: a conundrum.
Simon K Lee1, Hongbo Zhai, Howard I Maibach
1Department of Dermatology, University of California, School of Medicine, San Francisco, 94143-0989, USA.
Contact Dermatitis
|April 30, 2005
Summary
Iodine preparations can irritate normal skin, especially in petrolatum or isopropyl alcohol bases. Povidone-iodine (PVP-I) is less irritating, making it suitable for diagnostic patch testing.
Area of Science:
- Dermatology
- Allergology
- Toxicology
Background:
- Iodine antiseptics are common, but their irritant potential for patch testing is poorly understood.
- Limited data exists on iodine's irritant threshold in diagnostic patch testing.
Purpose of the Study:
- To evaluate the irritant potential of various iodine preparations and concentrations.
- To determine safe concentrations for diagnostic patch testing.
Main Methods:
- 24 healthy volunteers underwent patch testing with different iodine concentrations in petrolatum, isopropyl alcohol, and povidone-iodine.
- Reactions were assessed 2 and 4 days post-application using a standardized grading scale.
Main Results:
- Iodine in petrolatum and isopropyl alcohol caused mild-to-severe reactions, particularly at higher concentrations.
- 0.5% iodine in 70% isopropyl alcohol caused reactions in 33% of subjects.
- Povidone-iodine (PVP-I) showed minimal irritation, with only one subject reacting to 7.5% and 10% concentrations.
Conclusions:
- Iodine in petrolatum and isopropyl alcohol can be significantly irritating.
- Petrolatum may enhance iodine's irritancy, while alcohol may increase penetration.
- PVP-I is relatively non-irritant due to its complexed iodine.
- Recommended patch test concentrations: <1% iodine in petrolatum, <0.5% in 70% isopropyl alcohol, and 10% PVP-I.