A Child Presenting With Cyanosis – Differential Diagnosis

Cyanosis refers to the bluish skin color attributable most often to the presence of desaturated hemoglobin ( 5g/dl ). Primary etiologies include respiratory, cardiac, circulatory and nervous system disorders, as well as abnormal hemoglobin.

Respiratory Diseases

1. Lung disease

• Newborn: Lung hypoplasia , Diaphragmatic hernia, respiratory distress syndrome, transient tachypnea of the newborn, Bronchopulmonary dysplasia, Pulmonary interstitial emphysema, Congenital adematoid malformation, Meconium aspiration.
• Infectious: Pneumonia, Pneumonitis, Bronchiolitis.
• Asthma
• Cystic fibrosis
• Infiltrative disease: Pulmonary hemosiderosis, sarcoidosis

2. Airway abnormalities or Obstruction

• Congenital: choanal atresia, macroglossia, micrognathia, laryngeal web, tracheal stenosis, vascular ring, tracheoesophageal fistula.
• Infectious: Acute epiglottitis, croup, retropharyngeal abscess, laryngospasm.
• Traumatic: Vocal cord injury, pneumothorax, pneumomediastinum
• Others: lymphoma, cystic hygroma, goiter, laryngeal hemangioma or neoplasm, foreign body, obesity.

3. Trauma

• Pneumothorax, pneumomediastinum, vocal cord injury.

Pulmonary Vascular Diseases

1. Primary pulmonary hypertension

• Cyanosis requires a right to left shunt at the atrial or ductal level unless lung disease is present.

2. Pulmonary arteriovenous malformation

• Idiopathic or associated with congenital heart, hepatic or portal disease.

Cardiac Diseases

1. Cyanotic congenital heart diseases: These include 

• Transposition of great arteries, 
• hypoplastic left heart syndrome, 
• tetralogy of fallot, 
• truncuc arteriosus, 
• tricuspid atresia, 
• total anomalous pulmonary venous connection
• pulomonary atresia, 
• ebstein anomaly of tricuspid valve.

2. Persistent pulmonary hypertension of the newborn

3. Severe congestive heart failure

• As a result of congenital heart disease or acquired heart disease or infection ( myocarditis )

Circulatory Disorders
Cyanosis is the result of increased venous desaturation due to increased extraction of oxygen in peripheral tissues from diminished supply of blood to those tissues.

Conditions include :

• Shock
• Sepsis
• Hypogycemia
• Cardiomyopathy
• Vena cava obstruction
• Hypotension
• Peripheral Cyanosis

Neurologic Problems

1. Apnea

• Prematurity, 
• cereberal anomalies, 
• intracranial hemorrhage,
•  meningitis or 
• encephalitis

2. Breath holding spells

3. Respiratory muscle weakness

• Myotonic or muscular dystrophy,
• Gullain barre syndrome, 
• Myasthenia gravis , 
• infant botulism

4. Seizures

Hemoglobin Abnormalities

• Methemoglobinemia
• Low oxygen affinity hemoglobin
• Polycythemia or hyperviscosity syndrome