Table 1.

Statements

Diagnostics

The occupational type 1 allergy of greatest concern is occupational asthma; exposure‐related type 1 allergic rhinitis, conjunctivitis, and protein contact dermatitis also play a role

The diagnoses of occupational type 1 respiratory allergies follows an algorithm approach, starting with clinical and qualified occupational history, followed by confirmation of the disease with objective methods and allergy testing (SPT test or sIgE measurement), and, if needed, spirometry monitoring during work shifts or specific nasal challenge or SIC

Commercial sIgE tests generally lack transparent information on the allergen preparation used, applied standardization and quality control

In‐house tests mostly do not follow appropriate standardization and quality control; they differ from place to place considerably and do not allow comparison of the results definitively

There are limited commercial occupational allergens available on CAP. This necessitates specialized laboratories to provide bespoke “in‐house” assays for novel putative and allergens which are not available on CAP

Negative results from a bespoke in‐house assay for putative novel allergens do not necessarily imply a negative test, if there are no positive controls. sIgE tests are only as good as the composition of the allergens used in the assay. Thus, we need to ensure that for any sIgE measurement, we use the appropriate allergens

The laboratory should always assess the performance of sIgE assay by carrying out a clinical audit. The performance of any sIgE test, whether it is RAST or CAP, is very dependent on allergen used and the positive cut off value

CAP, RAST, and other methods for measurement of sIgE can give similar sensitivity to skin prick test when the same allergen is used for both test, for example, 95% for protease and cellulase, 98% for amylase, 99% rat urine

sIgE to HMW allergens provide acceptable sensitivity and specificity and are very useful as a diagnostic test

Specific IgE assays to LMW allergens are more problematic and dependent on the allergen investigated. sIgE measurement to isocyanates is specific but not sensitive, whereas sIgE to acid anhydride could have acceptable sensitivity and specificity, which needs to be assessed with larger cohorts. To date, we are unable to measure sIgE for platinum salts. Thus each low molecular weight allergen must be considered case by case

By use of sIgE tests HMW allergens provide acceptable sensitivity and specificity mostly above 0.7 kUA/l. This is especially shown for extracts from cereals, latex, enzymes, bovine epithelium and bovine dander, molds, insects, and for particular approaches with recombinant allergen components

Some wood extracts and LMW agents such as diisocyanates, acid anhydrides provide much lower sensitivity than confirmed HMW allergens; obviously, this is at least in part due to heterogenous patho‐mechanisms including irritant effects

Prevention

Early diagnosis of respiratory allergies combined with avoidance of the causative allergen is important because it prevents the allergy march from rhinitis to asthma, as well as chronification and deterioration of the disorders

Exposure assessment

Standard chemical air sampling and analysis methods exist for many of the low molecular weight allergens, however, in many cases exposure to these electrophilic chemicals is not just to the monomeric form. Exposure can be to a mixture of monomers, polymers and prepolymeric forms, but analytical methods are mainly only for monitoring the monomeric forms

Exposure assessment for characterizing levels leading to immunological sensitization (vs. asthma elicitation) is extremely difficult and in general lacking. This includes both respiratory and dermal sensitizing events

Biomarkers of exposure have been reported (especially for LMW allergens) in the literature, (eg, allergen metabolites or adducts), but they have not always been used as an exposure monitoring tool

Exposure monitoring for high molecular weight allergens may entail measurement of multiple allergenic proteins, especially from natural products. The specific aeroallergen(s) responsible for disease may vary with the life cycle of that product

Quantitative dermal exposure assessment methods are lacking, which hinders the assessment of the level of dermal sensitization in subsequent asthma development

Early biomarkers of allergic sensitization, in addition to specific IgE are needed to prevent subsequent asthma development

Direct reading instruments with sufficient sensitivity are needed to monitor relevant worker exposure to agents known to cause occupational asthma