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Toxicological information

Sensitisation data (human)

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Administrative data

Endpoint:
sensitisation data (humans)
Type of information:
other: clinical study
Adequacy of study:
supporting study
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: iron oxide was only tested among few patients which showed positive reactions to iron salts in the first test

Data source

Reference
Reference Type:
publication
Title:
Contact hypersensitivity to iron.
Author:
Hemmer W, Focke M, Wantke F, Gotz M, Jarisch R.
Year:
1996
Bibliographic source:
Contact Dermatitis 34(3):219-220

Materials and methods

Type of sensitisation studied:
skin
Study type:
other: clinical study
Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Authors patch-tested 623 patients with suspected hypersensitivity to metals over a 2.5 year period. Persons sensitive to ferric chloride (FeCl3) and ferrous sulfate (FeSO4) (5 positive, 2 suspicious) were further challenged with other iron compounds including iron oxide.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Iron (III) oxide
- Analytical purity: 1.44% in petrolatum

Method

Type of population:
general
Ethical approval:
not specified
Subjects:
Persons presenting to an allergy clinic in Austria.
- Number of subjects exposed: 623
- Sex: Male and Female
:
Clinical history:
- History of allergy or casuistics for study subject or populations: Two positive retested cases. Case 1 had a stainless steel implant removed due to swelling while the case 2 had a history of metal-induced eczema
- Exposure history: case 1 - stainless steel prosthesis; case 2 - no history of iron contact
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: patch test (epicutaneous test)

Results and discussion

Results of examinations:
NO. OF PERSONS WITH/OUT REACTIONS COMPARED TO STUDY POPULATION
- Number of subjects with positive reactions: First test - 5 positive and 2 suspicious to ferrous salts; Second test (6 of 7 original patients) - 2 re-confirmed to ferrous salts; no reaction to iron oxide

RESULT OF CASE REPORT: The patients' positive reactions to iron were of no clear clinical relevance. Iron does not seem to play a role as a contact allergen.

Applicant's summary and conclusion

Executive summary:

Over 2.5 years, 623 patients that attended an Austrian allergy clinic were patch-tested for hypersensitivity to metals, including iron salts. Of those patients, only 5 had positive results and 2 had suspicious results. These 7 were tested for other sensitivity to iron, including iron oxides. Upon retest of 6 of the 7, only 2 had re-confirmed iron sensitivity, none to iron oxide. The positive reactions of these patients did not have much clinical significance, though implantation of a stainless steel prosthesis might have been connected to case 1's reaction. Positive patch-test results should be investigated because reactions cannot be confirmed on retest. In these results, iron sensitivity was always associated with nickel and cobalt sensitivity, which raises the probability of cross-reactivity.