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This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
Key points
- Achalasia causes dysphagia to solids and liquids from the beginning
- Barium esophagram: dilated esophagus with bird-beak tapering
- Gold standard diagnosis: high-resolution manometry showing impaired LES relaxation and aperistalsis
- Pseudoachalasia from malignancy is suggested by older age, rapid progression, marked weight loss, or difficult endoscope passage
- Definitive therapy: pneumatic dilation, Heller myotomy, or POEM; botulinum toxin for poor candidates
Overview
Achalasia results from degeneration of inhibitory neurons in the myenteric plexus, causing failure of LES relaxation and absent peristalsis. Food and secretions accumulate, producing regurgitation, aspiration, chest pain, and weight loss.
Epidemiology
Achalasia is uncommon and typically presents in adults between ages 25 and 60. Pseudoachalasia is critical to exclude because gastroesophageal junction cancer can mimic achalasia.
Clinical Features
Symptoms
Progressive dysphagia to solids and liquids
Regurgitation of undigested food, especially at night
Chest pain or heartburn-like symptoms
Cough, aspiration, recurrent pneumonia
Rapid weight loss or older onset suggests malignancy
Signs
Often normal exam
Weight loss may be present
Signs of aspiration pneumonia
Supraclavicular nodes or cachexia suggests cancer
Investigations
First-line
Barium esophagramBird-beak tapering, esophageal dilation, retained contrast
Upper endoscopyExclude mechanical obstruction or pseudoachalasia
High-resolution manometryGold standard; impaired EGJ relaxation and aperistalsis
Second-line
Timed barium esophagramAssesses emptying after therapy
Chest imagingIf aspiration or malignancy concern
Specialist
CT/EUSIf pseudoachalasia suspected
pH testingIf reflux symptoms after therapy
Management
ACG Clinical Guideline: Achalasia 20201
Definitive therapy
- Pneumatic dilation effective but perforation risk
- Laparoscopic Heller myotomy with partial fundoplication
- POEM especially effective for type III but reflux common
2
Poor procedural candidates
- Botulinum toxin provides temporary relief
- Nitrates or calcium-channel blockers have limited benefit
3
After treatment
- Monitor for GERD
- Evaluate recurrent symptoms for incomplete therapy, reflux stricture, or malignancy
- Aspiration precautions while awaiting therapy
Complications
- Aspiration pneumonia: Nocturnal regurgitation.
- Megaesophagus: Severe chronic dilation.
- Weight loss: Impaired intake.
- Squamous cell carcinoma: Increased long-term risk.
USMLE Step 2 CK Exam Tips
- 1Dysphagia to solids and liquids from onset = motility disorder
- 2Progressive solids-only then liquids = mechanical obstruction/cancer
- 3Bird-beak is classic; manometry is diagnostic
- 4Endoscopy excludes pseudoachalasia
- 5Older patient + rapid weight loss = pseudoachalasia
- 6POEM works well for type III but reflux risk is higher
- 7Botulinum toxin is for frail patients
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