A 15-month-old girl is brought to the family physician by her parents due to a sudden onset of high fever reaching 104° F (40° C) for the past four days. The parents report that the child has been irritable but otherwise appears well, with no signs of respiratory or gastrointestinal illness. She has not been pulling on her ears. She has been taking fluids well and urinating normally. Today, the fever resolved abruptly, and a rash appeared on her chest and abdomen. Past medical history is negative, and she has received all age-appropriate immunizations. The child is afebrile with normal vital sings. On physical examination, there is a diffuse macular rash on her trunk. The tympanic membranes are normal, and the oropharynx is unremarkable with moist mucous membranes. Examination of the heart and lungs is unremarkable.
D) Roseola infantum
Roseola infantum is a common viral infection in young children, typically under 3 years of age. It is typically caused by human herpesvirus 6 (HHV-6) and occasionally by HHV-7. The disease often begins with a sudden high fever, which can reach up to 104° F (40° C) and lasts for about 3 to 5 days. During this febrile period, children may appear irritable but generally do not exhibit other symptoms of illness. As the fever subsides, a rash appears. The rash associated with roseola is macular or maculopapular and typically starts on the trunk, spreading to the neck and extremities. It is usually not itchy and fades within a few days. The diagnosis of roseola is primarily clinical, based on the characteristic pattern of high fever followed by rash. Laboratory tests are generally not required. While roseola is usually benign, the high fever can sometimes lead to febrile seizures, which are the most common complication. Treatment for roseola is supportive, focusing on managing fever and ensuring adequate hydration. Antipyretics like acetaminophen or ibuprofen can be used to reduce fever.
Answer choice A: Chickenpox, is incorrect. Chickenpox presents with a vesicular rash that appears in crops, not a sudden rash following fever resolution.
Answer choice B: Fifth disease (erythema infectiosum), is incorrect. Fifth disease presents with a "slapped cheek" rash and lacy reticular rash on the body, not the pattern seen in roseola.
Answer choice C: Measles, is incorrect. Measles presents with a rash that begins on the face and spreads downward, along with Koplik spots, not the pattern seen in roseola.
Answer choice E: Rubella, is incorrect. Rubella presents with a rash that begins on the face and spreads downward and is usually associated with mild symptoms, not the high fever seen in roseola.
Key Learning Point
Roseola infantum typically presents in a child under 3 years with a classic progression of high fever with no apparent cause for approximately 3-5 days followed by an abrupt return to normal temperature just as a diffuse macular or maculopapular rash appears on the chest or abdomen. Roseola infantum is caused by human herpesvirus type 6. The diagnosis is clinical and treatment is supportive.
