Figure 1 (A) Blood smear on day 19 of phenazopyridine, one day post red cell transfusion. Wrights Giemsa stain, 100X (B) Blood smear on day 25 of phenazopyridine, 6 days post red cell transfusion. Arrows indicate “bite,” “blister,” and “apple core” red cells. Wrights Giemsa stain 100X (C) Blood smear 10 days after phenazopyridine discontinued, 10 days post red cell transfusion. Wrights Giemsa stain 100X