Björn Edman

Clinical relevance of contact allergy to gold sodium thiosulfate

BACKGROUND In our routinely patch tested patients with dermatitis gold was shown to be the second most common sensitizer. In most patients it was difficult to explain the source of sensitization to gold and to see any clinical relevance. OBJECTIVE Our purpose was to elucidate the clinical relevance of contact allergy to gold sodium thiosulfate. METHODS A questionnaire on gold exposure and gold sensitivity was answered by 156 consecutive patients with dermatitis. In another group of 1056 routinely tested patients data were collected and analyzed regarding factors such as profession, atopy, localization of the dermatitis, and presence of contact allergies. RESULTS Gold allergy was overrepresented in those having dental gold. In persons with contact allergy to gold a dermatitis on the ears, fingers, or eye area was most frequent. CONCLUSION Exposure to gold jewelry and to dental gold may be important in the sensitization and elicitation of dermatitis.

Time trends in Swedish patch test data from 1992 to 2000. A multi-centre study based on age- and sex-adjusted results of the Swedish standard series.

Allergic contact dermatitis is recognized as a public health problem and some major allergens have been subject to intervention aiming at lowering skin exposure. There is an obvious interest in evaluating the effect of such interventions. Population studies are difficult to perform and epidemiological studies based on clinical data from testing patients with contact dermatitis are common surrogates. Our objective was to gather Swedish clinical standard series test data on two occasions in order to monitor trends in sensitization rates. Consecutive patch test results from the Swedish standard series were collected from 9 centres from 1991 to 1993 and from 1999 to 2001. In total, 3680 and 3790 patients, respectively, were included. Crude, age‐adjusted and age‐stratified prevalence are given separately for women and men. Our top 10 allergens are much in line with newly published European test data. Significant changes among those allergens are increasing sensitization rates for Myroxylon pereirae and decreasing rates for colophony, 5‐chloro‐2‐methyl‐4‐isothiazolin‐3‐one, Amerchol L 101 and thiuram mix. Nickel allergy is decreasing among young women. Among less common allergens, a noteworthy increase of sensitization to 4‐phenylendiamine is found. In conclusion, significant trends in sensitization rates of important allergen, reflecting changes in exposure, have been found.

A study on expert reading of patch test reactions: inter-individual accordance

To diagnose allergic or irritant contact dermatitis, a clinically relevant contact allergy has to be demonstrated or ruled out, respectively. Although patch testing has been used for 100 years, it remains the method of choice for diagnosing contact allergy. A disadvantage of patch testing is that reading is subjective, based on inspection and palpation of the test area, implying that the assessment is subject to the readers knowledge and experience. This study was carried out to investigate the accordance in reading patch test reactions between 5 dermatologists. 4 groups, each with 10 patients, participated. Within each group, all 10 were allergic to one and the same sensitizer; nickel, epoxy resin, ethylenediamine, or Kathon CG. The sensitizers were tested in serial dilutions and applied randomly to the back. The tests were read independently by the dermatologists in a blinded fashion. A protocol was used where the dermatologists had to note the presence of the morphological features erythema, infiltration, papules, vesicles, and bullae. In this way, it was possible to allocate the various readings into 4 classification systems, 3 European and one American, although the definition of the various classifications might differ slightly. Based on the readings and classifications, it was possible to calculate the degree of accordance within the 4 systems used. It was also possible to analyze the degree of accordance for the various morphological features. Total accordance for the 5 reading dermatologists for positive and negative test reactions was noted in 36% and 46%, respectively. The 3 European systems require homogenous erythema and infiltration for a reaction to be classified as allergic, while the American system also requires the presence of papules. Therefore, a higher number of allergic reactions (9%) was obtained with the European systems. Between the 4 classification systems, there were statistically significant differences, with the highest number of deviations for the system in which papules had discriminatory significance. When looking at the various morphological features, papules were most difficult to assess, followed by vesicles. Preferably, a classification system should not depend on papules. In conclusion, there was good accordance among the dermatologists in reading patch test reactions, since the 5 dermatologists read 82% of all tests similarly.

Trends and forecasts for standard allergens in a 12‐year patch test material

Results from 12 years of patch testing were statistically analysed to establish changes in the incidence of individual contact allergies. Significant trends were found for y allergens. A marked increase was evident for nickel and cobalt. The analysis made it possible to forecast the future development of separate contact allergies.

Sites of contact dermatitis in relationship to particular allergens

A study of 1016 patients Over a period of 2 years has been performed by using the DALUK computer system in order to find correlations between eczema sties and particular allergens. The study includes control material of patients with other contact allergies or with negative patch tests. The investigation confirms some well‐known correlations, e.g., between lanolin allergy and dermatitis of the lower leg, and between nickel allergy and dermatitis of the palm. Several new correlations are also described. e.g., chromium allergy and dermatitis of the buck of the trunk, allergy to balsam of Peru and dermatitis of the forehead and cheek.

Computerized analysis of concomitant contact allergens

A statistical study was conducted on 3697 patch‐tested patterns in order to find any cross‐reacting or concomitant allergens, 44 correlations were found 3 were well‐known cross‐reacting substances (e.g., benzocaine and p‐phenylenediamine). 7 were unlikely, probably random, findings and the remaining 27 were considered to be either new Cross‐reacting allergens (e.g., promethazine and azo dyes) or concomitant allergens found in the same kind of products (e.g., kickel and cobalt in alloys, ethylenediamine and neomycin in Kenacombin cream®, colophony and carba‐mix in adhesive bandage).

Seasonal influence on patch test results

At least 3 studies have previously tested the hypothesis that patch test results have a seasonal variation, either due to the influence of sunlight (1, 2), or for other reasons (3). Bruze (1) found that this was true,· but Dooms-Goossens et a!. (2) and Hjorth (3) did not. However, it is found that UVB-light influences the elicitation of allergic contact dermatitis (4). In order to clarify this, data from 3063 patchtested patients (1983-1987), traced from the DALUK data base (5), were analyzed statistically for seasonal variation. The test of seasonal variation (6) was applied to the positive outcome per month, defined as the number of patients positive to the standard series divided by the total number of patients patch tested (Fig. 1 ). It was found that a seasonal variation existed (p=0.021), with a peak value in January (45%) and a low in June (24%). The sex and age distribution from month to month did not vary at all. Furthermore, the seasonal variation did not differ among the co=onest allergens (nickel, cobalt, fragrancemix, colophony and neomycin). This result corresponds with that of Bruze (1). However, both studies were performed at the same latitude (southern Sweden, approx. 56°), while that of Dooms-Goossens (2) was performed in Belgium (latitude approx. 48°). The closer to the equator you are, the smaller the difference between su=er and winter radiation. The ratio of insolation between June and January is 20 in southern Sweden and only 5 in Belgium (7). There might also be a difference in sunbathing behavior between the 2 countries. Due to the short

Testing a purified lanolin preparation by a randomized procedure

Patients with a previous contact allergy to lanolin (wool alcohols and/or Amerchol L 101) were patch tested 1 to 4 years later with lanolin allergens, as well as purified anhydrous lanolin contained in a commercial cream. At this retest, only 20 out of 33 patients with a previous contact allergy to lanolin reacted to lanolin allergens, and only 1 to the purified lanolin (as is). None reacted to the commercial cream containing 6% purified lanolin, this being ascertained by patch test as well as by usage test. To avoid bias at reading, patch tests were applied in a randomized computer‐based order and read blindly.

True and false statistically found cross-reacting contact allergens

A statistical study was conducted on 3697 patchtested patients in order to find any cross-reacting or concomitant allergens. 37 various correlations were found. 3 were well-known cross-reacting substances (e.g., benzocaine and p-phenylenediamine). 7 were unlikely, probably random findings, and the remaining 27 were considered to be either new cross-reacting allergens (e.g., promethazine and azo dyes) or concomitant allergens found in the same kind of products (e.g., nickel and cobalt in alloys, ethylenediamine and neomycin in Kenacombin cream®, colophony and carba-mix in adhesive bandage).