Registration Dossier

Administrative data

Endpoint:
sensitisation data (humans)
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1994-1996
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:
Allergy to phosphorus sesquisulfide: 0.5 % pet. is a more appropriate concentration for patch testing
Author:
Abdullah A. et al.
Year:
1997
Bibliographic source:
Contact Dermatitis,37, pp. 210-212

Materials and methods

Type of sensitisation studied:
skin
Study type:
study with volunteers

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Patch test studies with phosphorus sesquisulfide were performed in 2 groups of 1000 patients each at two different concentrations (0.5 % and 1 % in pet) respectively in 1994 and in 1996.

Method

Type of population:
general
Subjects:
- Number of subjects exposed: 1000 patients tested for each group.
- Sex: males and females.
Clinical history:
The patients were selected from the Contact Dermatitis Clinic in The Birmingham Skin Centre. Approximately 1000 patients are referred for patch testing by general practitioners and other dermatologists each year. Regarding the group tested in 1994, all patients with positive results had a history of prior exposure to phosphorus sesquisulfide. Regarding the group tested in 1996, none of the patients with positive results had contact with phosphorus sesquisulfide or used 'strike anywhere' matches which are the common source of the allergen in the United Kingdom.
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: patch test

ADMINISTRATION: Phosphorus sesquisulfide at 0.5 % pet. for group tested in 1994 and phosphorus sesquisulfide at 1 % pet . for group tested in 1996.

EXAMINATIONS: the positive results were registered with the indication of the site of dermatitis.The readings were done by trained clinicians who performed patch testing on a regular basis, and the criteria as outlined by the International Contact Dermatitis Research Group were used. The incidence of positive patch tests at each concentration were compared using the χ2 test.

Results and discussion

Results of examinations:
NO. OF PERSONS WITH/OUT REACTIONS COMPARED TO STUDY POPULATION
- Number of subjects with positive reactions: 4 out of 1000 patients in the study performed in 1994 at 0.5 % pet. (3 patients with facial dermatitis) and 12 out of 1000 patients in the study performed in 1996 at 1 % in pet.(only 2 patients with facial dermatitis).

OTHER RESULTS:the increasing of test concentration from 0.5 % to 1 % caused a statistically significant increase in the clinical reactions .The laboratory attributed this to the irritant effect caused by the increased strength of the test substance and it recommend the test concentration to be 0.5 % phosphorous sesquisulfide in pet for the future tests. As conclusion, phosphorus sesquisulfide causes rare case of delayed hypersensitivity. This may well be explained by the fact that the general population as a whole is tending to use safety matches or lighters rather than the older non-safety matches.

Applicant's summary and conclusion

Conclusions:
Positive results of Phosphorus sesquisulfide were observed in patch tests on humans at concentration of 0.5 % and 1 % in pet.
Executive summary:

Patch test studies with phosphorus sesquisulfide were performed in 2 groups of 1000 patients each at two different concentrations (0.5 % and 1 % in pet) respectively in 1994 and in 1996. Some positive results were observed: 4 out of 1000 patients in the study performed in 1994 at 0.5 % pet. (3 patients with facial dermatitis) and 12 out of 1000 patients in the study performed in 1996 at 1 % in pet.(only 2 patients with facial dermatitis). The increasing of test concentration from 0.5 % to 1 % caused a statistically significant increase in the clinical reactions .The laboratory attributed this to the irritant effect caused by the increased strength of the test substance and it recommend the test concentration to be 0.5 % phosphorous sesquisulfide in pet for the future tests. As conclusion, phosphorus sesquisulfide causes rare case of delayed hypersensitivity. This may well be explained by the fact that the general population as a whole is tending to use safety matches or lighters rather than the older non-safety matches.