Differential Diagnosis for Progressive Difficulty Swallowing

Single Most Likely Diagnosis

• Achalasia: This condition is characterized by the inability of food to pass through the esophagus and into the stomach due to abnormal muscle contractions. The symptoms of progressive difficulty swallowing (dysphagia) for both liquids and solids, vomiting of digested food, and finding digested food on the pillow in the morning are classic for achalasia. The regurgitation of food, especially at night, is a hallmark symptom.

Other Likely Diagnoses

• Esophageal Stricture: This condition involves a narrowing of the esophagus, which can cause difficulty swallowing. While it more commonly affects solids, severe strictures can also impede the passage of liquids.
• Esophageal Cancer: Though less common in a 38-year-old, esophageal cancer can cause progressive dysphagia initially for solids and eventually for liquids as the tumor grows.
• Gastroesophageal Reflux Disease (GERD): While primarily associated with heartburn, severe GERD can lead to dysphagia and regurgitation of food.

Do Not Miss Diagnoses

• Esophageal Perforation: Although this would typically present acutely rather than over 18 months, any condition leading to esophageal rupture is an emergency.
• Mediastinal Mass: A mass in the mediastinum can compress the esophagus, leading to dysphagia. Given the potential for malignancy, it's crucial not to miss this diagnosis.

Rare Diagnoses

• Eosinophilic Esophagitis: An inflammatory condition of the esophagus that can cause dysphagia and food impaction, more commonly seen in patients with a history of atopy or eosinophilic gastrointestinal disorders.
• Scleroderma: A systemic disease that can lead to esophageal dysmotility and dysphagia due to fibrosis of the esophagus.
• Chagas Disease: Caused by Trypanosoma cruzi, this parasitic infection can lead to achalasia-like symptoms in its chronic phase, though it's rare in non-endemic areas without travel history.

Each of these diagnoses has a distinct set of symptoms and diagnostic approaches, ranging from endoscopy and manometry for achalasia and esophageal stricture, to imaging and biopsy for esophageal cancer and mediastinal masses.