Pediatrics · Year 3 · from Pediatrics

Case 3: Viral Exanthem - Roseola

Patient Demographics

  • Age: 11-month-old female
  • Sex: Female

Chief Complaint

"She had a high fever for 3 days, and now she has a rash."

History of Present Illness

An 11-month-old previously healthy female is brought in because of a new rash. She had high fevers (up to 40.5C) for the past 3 days. She was fussy during the fever but continued to drink and had no other symptoms. Parents gave acetaminophen and ibuprofen around the clock. She was seen in the ED on day 2 of fever; urinalysis and blood work were unremarkable, and she was sent home with instructions for supportive care. This morning, the fever resolved completely, and shortly afterward, parents noticed a red rash appearing first on her trunk that has now spread to her face and extremities. She is now acting like her normal self - playful and eating well.

Growth Parameters

  • Weight: 9.0 kg (50th percentile)
  • Length: 73 cm (50th percentile)
  • Head circumference: 45 cm (50th percentile)

Physical Examination

  • General: Happy, playful infant, no distress
  • Vital signs: T 37.2C, HR 120, RR 28
  • HEENT:
  • Anterior fontanelle soft, flat
  • Mild rhinorrhea
  • TMs normal
  • Posterior cervical and occipital lymphadenopathy (small, mobile, non-tender)
  • Cardiovascular: Normal
  • Respiratory: Clear
  • Abdomen: Soft, non-tender
  • Skin: Discrete, rose-pink, blanching maculopapular rash predominantly on trunk with spread to neck, face, and proximal extremities; non-pruritic; appears similar to rubella rash
  • Neurologic: Normal, alert, interactive

Workup

  • No additional workup needed - classic clinical presentation
  • Previous ED labs (for reference):
  • CBC: WBC 5,200 (lymphocyte predominant), Hgb 11.5, Platelets 220,000
  • UA: Normal
  • No blood culture obtained

Diagnosis

Roseola infantum (Exanthem subitum) - Human Herpesvirus 6 (HHV-6) infection

Clinical Reasoning

This is a textbook presentation of roseola: high fever (often 40-40.5C) for 3-4 days in an otherwise well-appearing infant, followed by defervescence and sudden appearance of a characteristic rose-pink macular/maculopapular rash starting on the trunk. The relative leukopenia with lymphocyte predominance is typical. The age (6 months to 2 years) and clinical course are pathognomonic. No laboratory confirmation is needed. The posterior cervical/occipital lymphadenopathy is a supportive finding.

Management

  1. Reassurance: This is a benign, self-limited viral illness
  2. Supportive care:
  • Antipyretics as needed (fever has resolved)
  • Adequate hydration
  1. Education:
  • Rash will fade within 1-3 days without treatment
  • No isolation needed once afebrile
  • The child is contagious during febrile phase, not during rash phase
  1. Return precautions:
  • Fever recurrence
  • New symptoms
  • Seizure (febrile seizures can occur with high fever in roseola)
  1. No antibiotics indicated

Clinical Image

Image Description: Clinical photograph demonstrating the characteristic rose-pink maculopapular rash of roseola infantum (exanthem subitum) on the trunk of an infant.

Source: Wikimedia Commons URL: https://commons.wikimedia.org/wiki/File:Roseola_on_a_21-month-old_girl.jpg License: CC BY 2.0

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