Differential Diagnosis for Adolescent Girl with Nausea, Vomiting, and Headache
Single Most Likely Diagnosis
- Viral Meningitis or Encephalitis: Although the patient tested positive for strep, the absence of fever, sore throat, or redness suggests that the strep test may be a false positive or an incidental finding. The symptoms of nausea, vomiting, and severe headache are more indicative of a viral infection affecting the central nervous system.
Other Likely Diagnoses
- Strep-Associated Conditions: Despite the lack of typical strep throat symptoms, it's possible that the patient has a strep-associated condition such as Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) or a strep-induced migraine, although these are less common.
- Migraine: The severe headache and associated nausea and vomiting could suggest a migraine, especially if the patient has a history of migraines. The strep test result could be coincidental.
- Viral Gastroenteritis: Although the primary complaint is a headache, the nausea and vomiting could also suggest a viral gastroenteritis, with the headache being a secondary symptom.
Do Not Miss Diagnoses
- Bacterial Meningitis: This is a medical emergency that requires prompt diagnosis and treatment. Although the patient does not have a fever, which is a common symptom, the severe headache and vomiting necessitate consideration of this diagnosis to avoid missing a potentially fatal condition.
- Subarachnoid Hemorrhage: A severe headache (often described as "the worst headache of my life") with nausea and vomiting could be indicative of a subarachnoid hemorrhage, which is a life-threatening condition requiring immediate medical attention.
- Encephalitis due to Other Causes: Encephalitis can be caused by various pathogens, including herpes simplex virus, and is a medical emergency.
Rare Diagnoses
- Intracranial Hypertension (Pseudotumor Cerebri): This condition can cause severe headaches, nausea, and vomiting, but it is less common and typically associated with other symptoms such as visual disturbances.
- Cerebral Venous Sinus Thrombosis: A rare condition that can cause headache, nausea, and vomiting, often associated with specific risk factors such as dehydration, oral contraceptive use, or hypercoagulable states.