Differential Diagnosis for Isolated Dilated Pupils in a Pediatric Patient
- Single Most Likely Diagnosis
- Anticholinergic toxicity (e.g., from medications or plants like jimsonweed): This is a common cause of dilated pupils in pediatric patients due to accidental ingestion of substances with anticholinergic properties.
- Other Likely Diagnoses
- Ocular trauma or irritation: Direct injury to the eye or irritation from a foreign body can cause pupil dilation.
- Adie's pupil (tonic pupil): A rare condition but more likely in the differential for isolated pupil dilation, characterized by a dilated pupil that reacts slowly to light.
- Third cranial nerve palsy: Although less common in pediatric patients without trauma or other neurological signs, it can cause pupil dilation due to paralysis of the parasympathetic nerves controlling pupil constriction.
- Do Not Miss Diagnoses
- Intracranial hemorrhage or mass: Although less common, these conditions can cause third cranial nerve palsy leading to pupil dilation and are critical to diagnose promptly due to their high morbidity and mortality.
- Brainstem injury or tumor: Similar to intracranial hemorrhage, these are less common but critical diagnoses that could present with isolated pupil dilation among other neurological signs.
- Meningitis: Inflammation of the meninges can cause increased intracranial pressure and cranial nerve palsies, including third cranial nerve palsy.
- Rare Diagnoses
- Congenital anomalies (e.g., congenital third cranial nerve palsy): These are rare conditions that could present with isolated pupil dilation.
- Neurosyphilis: A rare condition in pediatric patients but can cause a range of neurological symptoms including cranial nerve palsies.
- Botulism: Although rare, botulism can cause bilateral dilated pupils among other symptoms like muscle weakness and difficulty swallowing.