To prepare streusel topping:
In a medium bowl, stir together brown sugar, flour, rolled oats, ground cinnamon and ground allspice. Using pastry blender, cut in cold butter until the mixture resembles coarse crumbs. Set aside.
To prepare the bread: Preheat the oven to 375° Lightly grease a 9 x 5 loaf pan.
In a large bowl, stir together flour, sugar, baking powder and salt.
In another medium bowl, combine egg whites, milk, melted butter and lemon rind.
Add to flour mixture all at once and stir just until combined. Fold in blueberries.
Spoon bread into prepared loaf pan. Sprinkle with streusel topping.
Bake at 375 for 45 minutes or until a toothpick inserted in the center comes out clean.