Transient dilatation of the abdominal aorta in an infant with Kawasaki disease associated with thrombocytopenia.

We report on an 8 month old infant with Kawasaki disease associated with giant coronary aneurysms and transient thrombocytopenia. The patient's platelet count decreased to 24,000/mm3 on the 31st day of illness and fibrin degradation product was 5 micrograms/mL. Platelet count increased to the normal level (357,000/mm3) on the 35th day of illness. On the 27th day of illness, dilatation of the distal abdominal aorta adjacent to the bifurcation of the iliac arteries was observed by B-mode and color Doppler ultrasonography. It gradually returned to a normal size by the 45th day of illness. Aspirin administered from the 3rd to the 26th day of illness was replaced with flubioprophen because of liver dysfunction. Although we can not eliminate aspirin allergy as the cause of the transient thrombocytopenia, we think that the thrombocytopenia may have been related to the regression of the abdominal aorta.