A 9-month-old girl is brought to the emergency department after a 2-minute generalized seizure. The patient has had a fever for the past 12 hours and has been very fussy. She takes no medications and has no allergies. Her temperature is 39.4 C (103 F). Examination shows no abnormalities, and the patient is discharged home. Three days later, she is afebrile but develops a maculopapular rash affecting her trunk. Infection with which of the following is the most likely cause of this patient's condition?
Roseola infantum | |
Microbiology | HHV-6 most common |
Epidemiology | Age <2 |
Clinical features |
|
Management | Supportive care, reassurance |
HHV-6 = human herpesvirus 6. | |
This patient's presentation is consistent with roseola infantum, which is most commonly caused by human herpesvirus 6 (HHV-6). Febrile seizures can be caused by any febrile illness, and HHV-6 is one of the most common causes. However, most patients with HHV-6 infection do not develop seizures. Primary symptoms include high fever for 3-5 days followed by an erythematous maculopapular rash. The rash usually starts on the trunk and spreads to the face and extremities. The diagnosis is based on clinical presentation, and the infection is typically benign and self-limited.
(Choice A) Coxsackievirus A16 is a common cause of hand, foot, and mouth disease in children. Patients typically have erythematous oropharyngeal ulcers and maculopapular or vesicular lesions on the palms and soles.
(Choice B) Children with primary infection with herpes-simplex virus type 1 (HSV-1) have painful gingivostomatitis, often accompanied by fever and irritability. Neonatal HSV, most commonly caused by HSV-2, can present with fever and seizures in the newborn period.
(Choices D and F) Rubella and measles are vaccine-preventable viral infections that typically present with a maculopapular rash on the face that then spreads to the trunk and extremities; both infections can be distinguished from roseola by the pattern of rash development. In addition, patients with rubella often have Forchheimer spots on the soft palate, and measles is characterized by pathognomonic Koplik spots on buccal mucosa.
(Choice E) Parvovirus B19 causes erythema infectiosum, or fifth disease, which can present as a flulike illness followed by a characteristic "slapped cheek" rash and truncal reticular rash. Parvovirus B19 can be associated with aplastic crisis in those with pre-existing hematologic abnormalities (eg, sickle cell anemia).
(Choice G) Streptococcus pyogenes (Group A Streptococcus) can cause acute, exudative pharyngitis that is associated with fever, headache, and abdominal pain in school-aged children. It can also be accompanied by scarlet fever, a diffuse sandpaper-textured rash most prominent in skinfolds (eg, groin, axillae, antecubital fossa).
Educational objective:
Human herpesvirus 6 infection (roseola) classically presents with fever for 3-5 days followed by a truncal rash. It is also the most common cause of febrile seizures.