Abstract
The present work aims at elucidating the value of the skin window technique (SWT) concerning its specificity and its practical use in drug allergy. Twenty-three patients with presumed drug hypersensitivity were tested by the SWT, but the tests were not made until after subsidence of any eruption. The applications of the drug to the window site were done without any dilution. The cover slips were placed over abraded skin area with the suspected drug as antigens or saline controls. All slides were exchanged after 4 hours and 24 hours, and removed after 48 hours. They were stained with May-Grün-wald-Giemsa stain, and the differential cell count in 500 cells were made. Positive reactions, as noted by eosinophil counts of > 3 per cent, were seen at 14 of 18 test sites in 11 cases of definite drug hypersensitivity. However, negative reactions with 0 to 3 per cent eosinophils, were noted in all 5 cases of fixed drug eruption and in all 7 cases with equivocal drug hypersensitivity. Our results suggest the SWT to be of value in exanthematic drug allergy and of no help in detecting the antigenic drug of fixed drug eruption.
