Final answer:
The nurse should withhold the MMR vaccine from the toddler due to their history of an anaphylactic reaction to Neomycin, which is an ingredient in the MMR vaccine. Administering the DTaP and influenza vaccines do not appear to be contraindicated based on the information provided.
Step-by-step explanation:
A nurse in a provider's office is preparing to administer immunizations to a toddler during a well-child visit. Given that the toddler has an allergy to Neomycin with a history of anaphylactic reaction and considering that Neomycin is used in measles, mumps, and rubella (MMR) vaccines, the nurse should plan to withhold the MMR vaccine. Allergic reactions to vaccine components can cause serious harm, and anaphylaxis is a contraindication to vaccination with products containing that allergen.
Regarding the other options, withholding the diphtheria, tetanus, and pertussis (DTaP) vaccine or the influenza vaccine would not be necessary based on the provided history and physical, unless there is a specific contraindication not mentioned. The tuberculin skin test (TST) does need to be considered, but it is not typically contraindicated by a vaccine component allergy like Neomycin.