Current patch test results with the European baseline series and extensions to it from the 'European Surveillance System on Contact Allergy' network, 2007-2008.

BACKGROUND: The pattern of contact sensitization to the supposedly most important allergens assembled in the baseline series differs between countries, presumably at least partly because of exposure differences. Objectives. To describe the prevalence of contact sensitization to allergens tested in consecutive patients in the years 2007 and 2008, and to discuss possible differences. METHODS: Data from the 39 departments in 11 European countries comprising the European Surveillance System on Contact Allergy network (www.essca-dc.org) in this period have been pooled and analysed according to common standards. RESULTS: Patch test results with the European baseline series, and country-specific or department-specific additions to it, obtained in 25 181 patients, showed marked international variation. Metals and fragrances are still the most frequent allergens across Europe. Some allergens tested nationally may be useful future additions to the European baseline series, for example methylisothiazolinone, whereas a few long-term components of the European baseline series, namely primin and clioquinol, no longer warrant routine testing. CONCLUSIONS: The present analysis points to 'excess' prevalences of specific contact sensitization in some countries, although interpretation must be cautious if only few, and possibly specialized, centres are representing one country. A comparison as presented may help to target in-depth research into possible causes of 'excess' exposure, and/or consideration of methodological issues, including modifications to the baseline series.

The relationship between the proportion of the population tested annually and the rate of patients with positive patch test reactions.

BACKGROUND: Differences exist between the rates of patients with positive patch test reactions in different centres. OBJECTIVES: To explore the varying relationship between the percentage of patients with one or more positive reactions (rate of patients with positive reactions) and the proportion of the population tested annually (intensity of testing) by UK centres contributing to a shared data pool. METHODS: Patch test data were pooled from 11 UK centres that use the British Society for Cutaneous Allergy (BSCA), formerly known as the British Society for Contact Dermatitis, database. The catchment population size was estimated for each centre, and the rate of patients with positive reactions to allergens in the BSCA baseline series was calculated. RESULTS: As the intensity of testing increases, the rate of patients with positive reactions decreases. We found a strong linear correlation in the range of interest between the intensity of patch testing and the proportion of tests returning a positive result (R(2) = 0.598). CONCLUSION: Within the range of testing intensities covered by our reporting centres, the data show that as the intensity of testing increases, the rate of patients with positive reactions decreases.

The 'overall yield' with the baseline series - a useful addition to the array of MOAHLFA factors describing departmental characteristics of patch tested patients.

BACKGROUND: The proportion of patients with a positive patch test reaction to at least one allergen from the baseline series differs between departments. OBJECTIVES: To further define the above mentioned proportion, termed the 'P' measure, to examine factors associated with this measure, to describe its variation over time and between centres, and to discuss possible uses. PATIENTS AND METHODS: Eighteen departments have been 'long-term' participants in the Information Network of Departments of Dermatology (IVDK; www.ivdk.org), that is, since 1995 (1997 in two cases). In these departments, 80 919 consultations for patch testing with the baseline series, in the composition of the series valid at that time, were documented until December 2009. Bivariate and multifactorial analyses addressed factors associated with being patch test-positive to at least one baseline series allergen. RESULTS: Of the study population, 46.5% had at least one positive test reaction, with considerable variation being seen between centres and a general decline during the study period. Among other factors, female sex, occupational causation and a high suspicion of allergic contact dermatitis were significantly associated with having at least one positive patch test reaction to the baseline series. CONCLUSIONS: The 'P' measure should prove useful as another perspective on departmental characteristics, and should be reported along with established variables (MOAHLFA index).

The importance of propolis in patch testing--a multicentre survey.

BACKGROUND: Propolis is widely used in 'natural' cosmetics, remedies, and over-the-counter products. The incidence of propolis allergy is increasing, and cross-reaction with fragrance mix I (FMII), colophonium, and Myroxylon pereirae can occur. OBJECTIVES: To find out the prevalence and clinical relevance of positive patch tests to propolis and assess cross-reactions with Myroxylon pereirae, colophonium, FMI, and beeswax. METHODS: Two thousand eight hundred and twenty-eight subjects in 10 UK centres were patch tested with propolis and beeswax. Generic data were acquired from British Contact Dermatology Society (BCDS) database and further relevant information was requested by survey of participating centres. RESULTS: The prevalence of propolis allergy was 1.9% (55/2828). Out of these 55 subjects, only 4 (7.2%) were allergic to beeswax, 22 (40%) to Myroxylon pereirae, 15 (27.2%) to colophonium, and 6 (10.9%) to FMI. Additional data for 41 propolis allergic subjects were collected by questionnaire. Hands were the most common sites of involvement, and cosmetics were the most common source of contact. Eight out of 12 subjects reported improvement in eczema following avoidance of propolis. CONCLUSIONS: Propolis is an important allergen of increasing frequency and its inclusion in BCDS baseline series is appropriate. Cross-sensitivity to beeswax is rare.

The European baseline series in 10 European Countries, 2005/2006--results of the European Surveillance System on Contact Allergies (ESSCA).

BACKGROUND: Continual surveillance based on patch test results has proved useful for the identification of contact allergy. OBJECTIVES: To provide a current view on the spectrum of contact allergy to important sensitizers across Europe. PATIENTS/METHODS: Clinical and patch test data of 19 793 patients patch tested in 2005/2006 in the 31 participating departments from 10 European countries (the European Surveillance System on Contact Allergies' (ESSCA) www.essca-dc.org) were descriptively analysed, aggregated to four European regions. RESULTS: Nickel sulfate remains the most common allergen with standardized prevalences ranging from 19.7% (central Europe) to 24.4% (southern Europe). While a number of allergens shows limited variation across the four regions, such as Myroxylon pereirae (5.3-6.8%), cobalt chloride (6.2-8.8%) or thiuram mix (1.7-2.4%), the differences observed with other allergens may hint on underlying differences in exposures, for example: dichromate 2.4% in the UK (west) versus 4.5-5.9% in the remaining EU regions, methylchloroisothiazolinone/methylisothiazolinone 4.1% in the South versus 2.1-2.7% in the remaining regions. CONCLUSIONS: Notwithstanding residual methodological variation (affecting at least some 'difficult' allergens) tackled by ongoing efforts for standardization, a comparative analysis as presented provides (i) a broad overview on contact allergy frequencies and (ii) interesting starting points for further, in-depth investigation.

Tixocortol pivalate: what is the right concentration?

Tixocortol pivalate (TP) is a good marker for hydrocortisone allergy. The concentration of TP to be included in the standard series for patch testing has been the subject of debate. The objective of this study was to investigate the right concentration of TP to be included in the standard series for patch testing. 3747 consecutive patients with dermatitis were patch tested simultaneously with TP 1% and 0.1% in petrolatum at 9 centres in the UK from August 2004 to December 2005. Statistical analysis of the results was performed using STATISTICA, version 6 software. 41 patients had positive reactions of current or past relevance. 20 were positive for both concentrations, 13 positive only for TP 1% concentration, and 8 positive only for 0.1% concentration. Statistical analysis, using a two-tailed difference in proportions test, did not show a significant difference between the 2 concentrations (P=0.21). There was no statistically significant difference between the 2 concentrations of TP. The number of allergens that can be included in the standard series is limited for practical considerations. When testing for screening purposes, TP 1% is recommended.

Contact sensitivity to preservatives in the UK, 2004-2005: results of multicentre study.

Preservative sensitivity in the UK was last assessed in 2000. Given the changes in preservative usage, we have re-evaluated our patch test data in order to detect any changes in the trend of sensitization. The results of patch testing using the extended British Contact Dermatitis Society Standard series were collected from 9 dermatology centres in the UK. Positive reactions to each of 10 preservative allergens were captured together with the MOAHFLA indices for each centre. In total, 6958 patients were tested during the period 2004-2005. The current data were compared with previously published data. Formaldehyde and methylchloroisothiazolinone/methyl-isothiazolinone have the highest positivity rates at 2.0% and chloroxylenol the lowest at 0.2%. Parabens mix has the highest irritancy rate. Compared with the UK data in 2000, the positivity rate of imidazolidinyl urea (0.02 < P < 0.05) has significantly increased and that of methyldibromo glutaronitrile has significantly reduced (P < 0.001).

A multicentre review of the hairdressing allergens tested in the UK.

Allergens used for patch testing in the hairdressing series vary between dermatology centres in the UK. The aim of our study is to ascertain the hairdressing allergens currently in use and their test results in several dermatology centres in the UK. Data were obtained from databases in 9 dermatology departments. The allergens with positive results and current/past relevance were included in a new hairdressing series based on collective experience, for wider use and further evaluation.

A multicentre review of the footwear allergens tested in the UK.

Footwear allergens used for patch testing vary between dermatology centres in the UK. The aim of our study is to ascertain the footwear allergens currently in use and their test results in several dermatology centres in the UK. Data were obtained from databases in 9 dermatology departments. A new footwear series consisting of 19 allergens including those with positive results and current/past relevance in this study based on collective experience is proposed for wider use and further evaluation.