DAY-4 IS BETTER THAN DAY-3 FOR A SINGLE PATCH TEST READING

Readings were performed on day (D) 2, D3 and D4 after application of p atch tests in 88 patients. 90 patch test reactions in 49 patients were interpreted as allergic and of past or present relevance. A single D2 reading detected 58 of the allergic reactions, with 32 false-negative s and 23 false-positives. A single D3 reading detected 77 allergic rea ctions, with 13 false-negatives and 17 false-positives. A single D4 re ading detected 85 allergic reactions, with 5 false-negatives and 9 fal se-positives, Therefore, if only a single reading is feasible, it is b etter performed on D4 than on D3. (C) Munksgaard, 1996.