A 1-year-old boy is brought to the office for evaluation of fever and rash. He felt warm to his parents this morning and did not eat breakfast. Subsequently, the patient developed a maculopapular rash over the face and upper trunk. The child has a history of eczema treated with emollients at night and a topical corticosteroid as needed. He has no other medical issues. The patient received the measles-mumps-rubella vaccine and the varicella-zoster virus vaccine 7 days ago. He lives with his parents and 8-year-old twin sisters, all of whom are healthy and up to date on immunizations. Temperature is 39.8 C (103.6 F). On examination, there is a faint maculopapular rash on the face, shoulders, and upper chest that is nontender to palpation. The remainder of the examination is unremarkable. Which of the following is the best next step in management of this patient?

Question

A 1-year-old boy is brought to the office for evaluation of fever and rash.  He felt warm to his parents this morning and did not eat breakfast.  Subsequently, the patient developed a maculopapular rash over the face and upper trunk.  The child has a history of eczema treated with emollients at night and a topical corticosteroid as needed.  He has no other medical issues.  The patient received the measles-mumps-rubella vaccine and the varicella-zoster virus vaccine 7 days ago.  He lives with his parents and 8-year-old twin sisters, all of whom are healthy and up to date on immunizations.  Temperature is 39.8 C (103.6 F).  On examination, there is a faint maculopapular rash on the face, shoulders, and upper chest that is nontender to palpation.  The remainder of the examination is unremarkable.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

The measles-mumps-rubella (MMR) vaccination is recommended at age 1 and again at age 4. It is safe and effective, with mild reactions occurring in a minority (3-5%) of immunized patients. This child has fever and a maculopapular rash a week after receiving the MMR vaccine, which is most likely due to infection with vaccine-strain measles virus used in the vaccine. Although the virus is attenuated, it is a live virus and therefore can cause a mild version of measles within 1-3 weeks of immunization. No treatment is needed as the vaccine-strain illness is minor and self-limiting. Although less contagious than wild-type measles, the vaccine strain is also transmissible to others. Therefore, patients who develop a rash after MMR immunization should avoid contact with immunocompromised individuals until the rash has resolved. (Choice A) Airborne isolation, including an N95 respirator mask, is indicated for primary measles infection, which is extremely contagious and transmitted via aerosolized droplets. Vaccine-strain measles is considerably less infectious and does not require airborne precautions. N95 respirator mask (Choice B) Serology is used for the diagnosis of primary measles infection but not in the evaluation of reactions to the MMR vaccine. (Choice C) Oral antihistamines are used in the treatment of type 1 hypersensitivity reactions, which can occur immediately after immunization due to allergy against vaccine components (eg, gelatin, neomycin). Patients with type 1 hypersensitivity have wheezing, urticaria, or anaphylaxis. (Choice D) Oral antiviral therapy (eg, acyclovir) is indicated for high-risk patients with varicella infection, which presents with fever and vesicular rash in successive "crops." This child does not have varicella. (Choice F) Topical corticosteroids are used in the treatment of eczema (atopic dermatitis). Eczema is dry, scaly, and erythematous as well as often pruritic and is not associated with fever. Eczema Educational objective: The prevalence of measles has been reduced drastically by measles-mumps-rubella vaccination. The vaccine has an excellent safety profile, but within 1-3 weeks after immunization a small fraction of patients may develop a fever and mild rash that resolve without treatment. References: Safety of vaccines used for routine immunization of U.S. children: a systematic review. (http://www.ncbi.nlm.nih.gov/pubmed/25086160) A systematic review of human-to-human transmission of measles vaccine virus. (http://www.ncbi.nlm.nih.gov/pubmed/27083423)

A 1-Year-Old Boy Is Brought to the Office for Evaluation