A 2-year-old boy is brought into the emergency room with a complaint of fever for 6 days and the development of a limp. On examination, he is found to have an erythematous macular exanthem over his body, ocular conjunctivitis, dry and cracked lips, a red throat, and cervical lymphadenopathy. There is a grade 2/6 vibratory systolic ejection murmur at the lower left sternal border. A white blood cell count and differential show predominant neutrophils with increased platelets on smear. Which of the following is the most likely diagnosis?
a. Scarlet fever
b. Rheumatic fever
c. Kawasaki disease
d. Juvenile rheumatoid arthritis
e. Infectious mononucleosis
the answer is below…
The United States Medical Licensing Examination, or USMLE for short, is a three-part licensing examination that is required in order to receive a license to practice medicine within the United States.
The USMLE assesses a physician’s ability to apply knowledge, concepts, and principles, and to determine fundamental patient-centered skills that are important in health and disease and that constitute the basis of safe and effective patient care.Examination committees composed of medical educators and clinicians from across the United States and its territories prepare the examination materials each year.
This exam is designed by the Federation of State Medical Boards and the National Board of Medical Examiners to determine whether or not an individual understands and can apply the knowledge necessary to practice medicine safely and intelligently.
The USMLE is actually comprised of three different exams that are referred to as steps, which examine the individual’s knowledge of specific topics related to the field of medicine such as basic science, medical knowledge, medical skills, clinical science, and the application of all of these skills and areas of knowledge in the medical field.
All three steps of the USMLE include a series of computerized multiple-choice questions, but the format of the exam and the information covered in each multiple-choice section is different for each step of the USMLE. The USMLE Step II also has a clinical skills portion that examines an individual’s ability to work with real patients and the USMLE Step III has a computerized patient simulation portion in addition to the multiple-choice section of the exam. In order for an individual to receive a license to practice medicine, the individual must pass all three steps of the USMLE.
The correct answer is c; Kawasaki disease.
Many conditions can be associated with prolonged fever, a limp caused by arthralgia, exanthem, adenopathy, and pharyngitis. Conjunctivitis, however, is suggestive of Kawasaki disease. The fissured lips, although common in Kawasaki disease, could occur after a long period of fever from any cause if the child became dehydrated. The predominance of neutrophils and high sedimentation rate are common to all. An increase in platelets within this constellation of symptoms, however, is found only in Kawasaki disease. Kawasaki disease presents as a picture of prolonged fever, rash, epidermal peeling on the hands and feet (especially around the fingertips), conjunctivitis, lymphadenopathy, fissured lips, oropharyngeal mucosal erythema, and arthralgia or arthritis. The diagnosis is still possible in the absence of one or two of these physical findings. Coronary artery aneurysms can develop, as can aneurysms in other areas. Initial treatment is typically IVIG and high-dose aspirin. The child’s fever will usually defervesce shortly after the infusion. Aspirin is typically kept at a higher dose until the platelet count begins to decrease, and then is continued at a lower dose for several weeks. While bacterial infection is in the differential diagnosis for this patient’s presentation and blood cultures are usually part of the evaluation, intravenous vancomycin should be reserved for a culture-proven susceptible organism resistant to other antibiotics, or as empiric therapy in a critically ill patient.