Differential Diagnosis for a Child with Fever, Vomiting, Diarrhea, and Itchy Rashes
- Single Most Likely Diagnosis
- Viral Exanthem (e.g., Roseola, Measles, or Enterovirus infection): This is a common cause of fever and rash in children. The sequence of symptoms (fever, followed by vomiting, diarrhea, and then rash) fits with several viral exanthems, which are known for their prodromal phase of fever and nonspecific symptoms before the onset of rash.
- Other Likely Diagnoses
- Gastroenteritis with secondary skin infection or allergic reaction: The initial symptoms of fever, vomiting, and diarrhea could be due to a gastrointestinal infection. The subsequent itchy rash might represent a secondary bacterial infection of the skin (like impetigo) or an allergic reaction to a medication or food.
- Infectious Mononucleosis (Mono): Caused by Epstein-Barr virus (EBV), mono can present with fever, gastrointestinal symptoms, and later, a rash, especially if the patient is taking ampicillin or a similar antibiotic.
- Do Not Miss Diagnoses
- Meningococcemia: Although less common, this condition is life-threatening and can present with fever, rash, and gastrointestinal symptoms. The rash in meningococcemia is typically petechial or purpuric, not itchy, but early stages can be misleading.
- Kawasaki Disease: An acute febrile illness of childhood that can lead to coronary artery aneurysms if not treated promptly. It classically presents with fever, rash, conjunctivitis, cervical lymphadenopathy, and changes to the lips and oral cavity.
- Rare Diagnoses
- Erythema Infectiosum (Fifth Disease): Caused by Parvovirus B19, it typically presents with a "slapped-cheek" appearance followed by a lacy rash on the body. While it's more common in children, the initial gastrointestinal symptoms are less typical for this condition.
- Scarlet Fever: Caused by Group A beta-hemolytic streptococci, it presents with fever, sore throat, and a characteristic rash that feels like sandpaper. The rash is usually accompanied by a strawberry tongue and is not typically itchy.