Differential Diagnosis for a Child with High Fever then Rash
- Single most likely diagnosis
- Roseola infantum: This is a common illness in children, typically caused by human herpesvirus 6 (HHV-6) or human herpesvirus 7 (HHV-7), characterized by a high fever followed by a rash after the fever resolves.
- Other Likely diagnoses
- Scarlet fever: Caused by Group A beta-hemolytic streptococci, it presents with a high fever, sore throat, and a characteristic rash.
- Measles: Although vaccination has reduced its incidence, measles can still occur, presenting with fever, cough, runny nose, and a rash.
- Rubella: Another viral illness that can cause fever and rash, though it's less common due to vaccination.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningococcemia: A severe bacterial infection that can cause fever, rash, and has a high mortality rate if not treated promptly.
- Rocky Mountain spotted fever: A tick-borne illness that can present with fever and rash, and is critical to diagnose early due to its potential severity.
- Kawasaki disease: An acute febrile illness of childhood that can lead to cardiac complications if not recognized and treated.
- Rare diagnoses
- Enteroviral infections (e.g., hand-foot-and-mouth disease): While common, the specific presentation of high fever followed by rash is less typical.
- Erythema infectiosum (Fifth disease): Caused by parvovirus B19, it's characterized by a "slapped cheek" appearance and lacy rash, but high fever is not always a prominent feature.
- Juvenile idiopathic arthritis (Systemic JIA): Can present with fever and rash, but is less common and diagnosis often requires consideration of other systemic symptoms and inflammatory markers.