A 2-year-old boy is brought to the office due to fever. For the past 6 days, he has had a fever of 39 C (102.2 F) to 40 C (104 F) that subsides minimally with acetaminophen. Yesterday, his mother noted a rash on his diaper area. Temperature is 39.2 C (102.6 F), pulse is 140/min, and respirations are 30/min. Physical examination shows an irritable boy. The patient's neck is supple with full range of motion. Both hands and feet are slightly erythematous and edematous, and a peeling rash is present over the perineal area. His eyes and lips appear as shown. The remainder of the examination is unremarkable. Which of the following is the most likely diagnosis?
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This patient has Kawasaki disease, an acute, inflammatory condition characterized by vasculitis of medium-sized arteries. Most cases occur in children age <5 with a peak incidence among those of East Asian ethnicity. The persistent release of proinflammatory cytokines causes irritability and a prolonged high fever that is often unresponsive to antipyretics.
Diagnosis is clinical, consisting of fever ≥5 days and ≥4 of the following findings:
A serious complication of Kawasaki disease is coronary artery inflammation leading to the development of coronary artery aneurysms, which can lead to myocardial ischemia, arrhythmias, and sudden death.
(Choice A) Pharyngoconjunctival fever due to adenovirus can present with prolonged fever and nonexudative conjunctivitis. In contrast to this case, however, patients typically have pharyngitis, not mucositis of the lips, and edematous extremities are not seen.
(Choice B) Hand, foot, and mouth disease caused by coxsackievirus presents with fever and rash on the palms and soles. However, discrete oropharyngeal sores would be seen, and conjunctivitis and extremity edema would not be expected.
(Choice D) In addition to conjunctivitis and fever, measles causes cough and coryza, neither of which is seen here. Oropharyngeal examination may reveal Koplik spots, or discrete buccal lesions, not diffuse labial erythema and inflammation. In addition, the measles rash is characterized by cephalocaudal spread of maculopapular lesions that subsequently darken and coalesce; this patient's isolated perineal rash is inconsistent with measles.
(Choice E) Scarlet fever presents with fever, strawberry tongue, and rash. Although the rash in scarlet fever can desquamate, it is sandpaper-textured, diffuse, and prominent along skin folds (eg, axillae, antecubital fossae). Moreover, exudative pharyngitis is usually present, and conjunctivitis would not be expected.
Educational objective:
Kawasaki disease is a vasculitis characterized by fever for ≥5 days and ≥4 of the following findings: nonexudative conjunctivitis, extremity changes, cervical lymphadenopathy, mucositis, and polymorphous rash.