After 6 weeks , the patients in the dapsone arm showed mean improvement over baseline in VAS ( 2.3 [ 95 % CI , 0.6-4 .1 ] , P = .01 ) , urticaria score ( -3.5 [ 95 % CI , -6.2 to -0.9 ] , P = .01 ) , and itch score ( -4.8 [ 95 % CI , -7.6 to -2.1 ] , P = .001 ) , whereas the placebo arm showed no improvement over baseline for VAS , urticaria , or itch scores .