Improvement of patch test allergen exposure by short-term local pressure.
Since false-negative results in patch testing may be due to insufficient skin contact with the allergen during exposure, we tried a modified test method by initially applying standardized pressure (10-kg sand bag for 15 min) on the test patches. Tests were simultaneously performed in 50 patients with and without local pressure. Comparing the results of both methods and (in some cases) to those after stripping the horny layers, positive contact sensitivity reactions could more often be detected after initial application of pressure.
D000485:Allergens; D003877:Dermatitis, Contact / Q000209:etiology; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008297:Male; D010328:Patch Tests / Q000379:methods*; D011312:Pressure; D012882:Skin Tests / Q000379:methods*
D000485:Allergens