Final answer:
A nurse should closely monitor for a maculopapular rash and chronic or recurrent diarrhea in a patient who has undergone stem cell transplantation for SCID, as these symptoms are indicative of graft-versus-host disease (GVHD).
Step-by-step explanation:
The nurse caring for a child who has undergone a stem cell transplantation for severe combined immune deficiency (SCID) would monitor for symptoms of graft-versus-host disease (GVHD). GVHD occurs when donor immune cells from a transplantation attack the recipient's organs. The hallmark symptoms of acute GVHD include a maculopapular rash, tissue damage to organs such as the skin, gastrointestinal tract, liver, and eyes, and potentially a cytokine storm. Chronic GVHD, which appears months after the transplantation, can have a wider range of symptoms.
Of the options provided, the nurse should closely monitor for C) Maculopapular rash and D) Chronic or recurrent diarrhea, as both are indicative of GVHD. The rash is especially significant because skin is often one of the first and most visibly affected organs, whilst gastrointestinal symptoms like diarrhea are indicative of potential damage to the GI tract.