Skin prick testing with standardized extracts from 3 different manufacturers. A comparative randomized study

Area of Science:

• Allergy and Immunology
• Dermatology
• Clinical Diagnostics

Background:

• Skin prick testing is a common method for diagnosing allergic diseases.
• Standardization of allergen extracts and testing methods can vary between manufacturers.
• Understanding inter-manufacturer variability is crucial for accurate allergy diagnosis.

Purpose of the Study:

• To compare the skin reactivity of allergen prick test panels from three different manufacturers.
• To assess the consistency and variability of allergen responses in routine clinical use.

Main Methods:

• Two hundred consecutive patients underwent skin prick testing with ten common aero-allergens.
• Allergen panels were sourced from three manufacturers: ALK (Soluprick SQ), DHS (Alphatest), and PHA (Phazet).
• Methods for allergen standardization, potency declaration, and lancet use differed across manufacturers.

Main Results:

• The coefficient of variation for allergen extracts was 0.31 for PHA, 0.13 for ALK, and 0.18 for DHS.
• Overall frequencies of positive patient reactions to allergens were generally similar across the three panels.
• The DHS panel showed fewer positive reactions to Timothy pollen, dog dander, and Dermatophagoides pteronyssinus compared to others.

Conclusions:

• Significant differences in allergen extract variability and specific allergen reactivity exist between manufacturers.
• Physicians should be aware of the allergenic activity differences in routine panels for accurate allergy diagnosis.
• Manufacturer-specific performance may influence the interpretation of skin prick test results.