Iodine

Sensitisation data (human)

Administrative data

Endpoint:

sensitisation data (humans)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Allergic contact dermatitis from povidone-iodine: a re-evaluation study

Author:

Lachapelle, J-M.

Year:

2005

Bibliographic source:

Contact Dermatitis 2005: 52: 9–10

Materials and methods

Type of sensitisation studied:

skin

Study type:

other: study with 500 consecutive patients

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

500 consecutive patients were patch tested with a 10% povidone-iodine (PVP-I) solution, diluted 10 times in water. Readings were made at 2 and 4 days.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Povidone-iodine

IUPAC Name:

Povidone-iodine

Method

Route of administration:

dermal

Details on study design:

500 consecutive patients attending the patch test clinic of the Department of Dermatology, Louvain University, were patch tested with a 10% PVP-I solution, diluted 10 times in water (PVP-I: 1%). 204 (40.8%) acknowledged that they had applied PVP-I on the skin or mucous membranes (in one or the other galenic form), often repeatedly. 196 (39.2%) denied having used it before or could not remember having done so.
The formulation of the PVP-I solution was: PVP-I 10%, ethanol, glycerol and water. Test material was the IQ Square Chamber Chemotechnique (Malmo, Sweden). Patch tests were applied for 2 days; 2 readings were made at 2 and 4 days. 2 weeks later, patients with a positive patch test (+ to +++) to PVP-I were put through a repeated open application test (ROAT) using the PVP-I solution, as is (i.e. 10% PVP-I). ROATs were performed on the volar aspect of the forearm (2 daily 5 x 5 cm applications for a maximum of 7 days).
The PVP-I solution was spread with a padded stick and allowed to dry (±5 min). The site of application was swabbed with water before each application

Results and discussion

Results of examinations:

14 of the 500 patients showed a positive patch test to PVP-I (2.8%). The scoring of positive patch tests was as follows: 6 +, 7 ++ and 1 +++, at 2 days. The tests were still positive at 4 days, but there was an overall reduction in the scores.

Only 2 of the 14 patients with a positive patch test to PVP-I showed a positive ROAT: 1 after 4 applications and 1 after 6 applications. The positive reactions were diffusely erythematous, slightly oedematous with follicular elevations looking like tiny papules. They were of current relevance. Indeed, both patients had applied PVP-I during the 2 months prior to patch testing and had experienced clinical signs of allergic contact dermatitis. 12 patients had a negative ROAT after 7 days (i.e., 14 applications).

Applicant's summary and conclusion

Conclusions:

The allergic contact dermatitis of iodine (PVP-solution) was evaluated in a human study. 500 consecutive patients attending the patch test clinic of the Department of Dermatology, Louvain University, were patch tested with a 10% PVP‐I solution, diluted 10 times in water (PVP‐I: 1%). 204 (40.8%) acknowledged that they had applied PVP-I on the skin or mucous membranes (in one or the other galenic form), often repeatedly. 196 (39.2%) denied having used it before or could not remember having done so. The formulation of the PVP‐I solution was: PVP-I 10%, ethanol, glycerol and water. 2 of the 500 patients had true allergic contact dermatitis from PVP-I (0.4%).

Executive summary:

The allergic contact dermatitis of iodine (PVP-solution) was evaluated in a human study. 500 consecutive patients attending the patch test clinic of the Department of Dermatology, Louvain University, were patch tested with a 10% PVP‐I solution, diluted 10 times in water (PVP‐I: 1%). 204 (40.8%) acknowledged that they had applied PVP-I on the skin or mucous membranes (in one or the other galenic form), often repeatedly. 196 (39.2%) denied having used it before or could not remember having done so. The formulation of the PVP‐I solution was: PVP-I 10%, ethanol, glycerol and water. 

 

Readings were made at 2 and 4 days. 14 of the 500 (2.8%) showed a positive test to PVP-I. The 14 positive patients to PVP-I were subjected to a repeated open application test (ROAT) with a PVP-I solution, as is; 2 of the 14 were recorded as positive. It was concluded that only 2 of the 500 patients had true allergic contact dermatitis from PVP-I (0.4%).