Interactive Quiz: Pain and Swelling in the Thigh

Answer: Pancytopenia

The patient was diagnosed with severe pancytopenia with cellulitis.

CBC results had been recorded as within the normal range before mesalamine had been initiated. Therefore, pancytopenia could have resulted from the potentiating effects of mesalamine on the 6-MP and budesonide combination regimen. This rapid occurrence of myelosuppression most likely resulted from mesalamine-induced inhibition of TPMT, leading to inhibition of the catabolism of 6-MP to inactive 6-MMP and accumulation of other active metabolites, particularly 6-TG nucleotides.