Differential Diagnosis for a 2-year-3-month-old Child with Persistent Cough
Single Most Likely Diagnosis
- Viral upper respiratory tract infection (URTI): Given the initial presentation of a non-productive cough without fever, difficulty breathing, or changes in feeding and sleeping patterns, and the fact that the cough worsened at night, a viral URTI is the most likely diagnosis. The child's age and the presence of similar episodes in the past that cleared up slowly also support this diagnosis.
Other Likely Diagnoses
- Asthma: The presence of a family history of bronchial asthma (paternal grandfather) and the child's symptoms of cough worsening at night, despite the absence of wheezing or other typical asthma symptoms, make asthma a possible diagnosis. The allergic reaction to amoxicillin and the response to phenylephrine (though not relieving the cough) may also suggest an allergic component.
- Allergic rhinitis: Similar to asthma, the presence of allergic reactions and a family history of asthma, along with the child's symptoms, could suggest allergic rhinitis as a cause for the persistent cough.
- Gastroesophageal reflux disease (GERD): The cough that worsens at night and is sometimes severe enough to induce vomiting could be indicative of GERD, especially if the child has a history of reflux or if the cough is associated with feeding.
Do Not Miss Diagnoses
- Pertussis (Whooping Cough): Although less likely due to the absence of a characteristic whoop and the child's vaccination status not being mentioned, pertussis can cause severe, persistent cough and is a critical diagnosis to consider due to its potential for severe complications and the need for public health intervention.
- Tuberculosis (TB): Given the family history of a chronic cough with blood-streaked sputum in an aunt (though the diagnosis is unknown), TB should be considered, especially if there's any exposure history or if the child has been in contact with someone with TB.
- Foreign body aspiration: Although the child is 2 years and 3 months old and the history does not specifically suggest an acute onset, foreign body aspiration can cause persistent cough and is a medical emergency.
Rare Diagnoses
- Cystic Fibrosis: This condition can cause chronic cough among other symptoms, but it's less likely without other supporting symptoms such as recurrent infections, failure to thrive, or steatorrhea.
- Primary ciliary dyskinesia (Kartagener syndrome): Characterized by chronic respiratory tract infections, this condition is rare and would typically present with other symptoms such as situs inversus.
- Habit cough: A psychological condition where the cough is a habit and not due to any organic cause. It's rare and usually seen in older children who can understand and verbalize their actions.