Internal Medicine Quiz
History
- 63-year-old male
- Cough with occasional haemoptysis
- Dysphagia
- Skin rash
- Progressive proximal muscle weakness
- Difficulty climbing stairs
- Unable to walk for last 5 days
- Dry-to-productive cough for 2 months
Examination
- Erythematous rash over upper back and shoulders
- Proximal muscle weakness involving hip and shoulder girdles
- Unable to mobilize independently
Investigations
- Chest X-ray PA view
- Non-homogenous opacity with irregular margin in right mid zone
MCQ Questions
1. Rash distribution is best described as:
A. Malar rash
B. Photosensitive rash
C. Shawl sign distribution
D. Discoid rash
E. Heliotrope rash
2. Most likely unifying diagnosis?
A. Polymyositis alone
B. Bronchial carcinoma with Dermatomyositis (paraneoplastic)
C. Myasthenia gravis
D. Guillain-Barré syndrome
E. Systemic sclerosis
3. NOT a typical skin finding?
A. Heliotrope rash
B. Gottron's papules
C. Periungual nail-fold capillary changes
D. Subcutaneous calcification
E. Target lesions
4. Best test to confirm muscle involvement?
A. Serum amylase
B. Creatine kinase levels
C. Liver function tests
D. Serum bilirubin
E. Random blood sugar
5. Key first-line treatment?
A. NSAIDs only
B. Glucocorticoids
C. Antibiotics
D. Antivirals
E. Beta-blockers
Brief Case Summary
An elderly man presented with haemoptysis, dysphagia, characteristic rash over the upper back, progressive proximal muscle weakness, and inability to walk. Imaging revealed an irregular right lung opacity.
Answer
Click to Reveal Answers
1. C — Shawl sign distribution
2. B — Bronchial carcinoma with Dermatomyositis (Paraneoplastic)
3. E — Target lesions
4. B — Creatine kinase levels
5. B — Glucocorticoids
Answer Explanation
Dermatomyositis is an inflammatory myopathy characterized by proximal muscle weakness and typical skin manifestations such as shawl sign, heliotrope rash, and Gottron papules. In older adults, it may occur as a paraneoplastic syndrome, commonly associated with lung malignancy.
Why Not Others?
- Polymyositis lacks characteristic skin findings.
- Myasthenia gravis causes fatigable weakness without rash.
- Guillain-Barré syndrome causes ascending weakness.
- Systemic sclerosis presents with skin tightening rather than inflammatory myopathy.
- Target lesions are typical of erythema multiforme, not dermatomyositis.
5 Brief Case Scenarios
- Middle-aged woman with heliotrope rash and elevated CK.
- Smoker with lung mass and proximal muscle weakness.
- Patient with Gottron papules and dysphagia.
- Cancer patient developing inflammatory myopathy.
- Elderly patient with shawl sign and muscle weakness.
Pathophysiology Simplified
Autoimmune-mediated muscle inflammation causes muscle fiber injury. Dermatomyositis also involves complement-mediated microvascular damage. Tumor antigens may trigger an immune response leading to paraneoplastic disease.
Physical Examination Pearls
- Check proximal muscle strength.
- Look for shawl sign.
- Look for heliotrope rash.
- Search for Gottron papules.
- Assess swallowing difficulty.
Investigation Findings
- Elevated CK
- Elevated aldolase
- Myopathic EMG changes
- MRI muscle edema
- Muscle biopsy showing inflammatory myopathy
- Underlying malignancy on imaging
Complications
- Aspiration pneumonia
- Respiratory muscle weakness
- Malnutrition
- Interstitial lung disease
- Cancer-related mortality
Management
- High-dose glucocorticoids
- Treat underlying malignancy
- Methotrexate or azathioprine
- IVIG for severe disease
- Physiotherapy and rehabilitation
Differential Diagnosis
- Polymyositis
- Myasthenia gravis
- Guillain-Barré syndrome
- Motor neuron disease
- Systemic lupus erythematosus
Clinical Pitfalls
- Missing occult malignancy screening.
- Assuming weakness is due to aging.
- Ignoring skin findings.
- Delayed CK testing.
- Overlooking dysphagia complications.
Clinical Pearls
- Dermatomyositis in elderly patients should prompt cancer screening.
- Shawl sign is highly suggestive.
- Dysphagia indicates severe disease.
- CK is usually elevated.
- Early treatment improves outcomes.
Monitoring & Follow-up
- Serial CK levels
- Muscle strength assessment
- Monitor swallowing function
- Cancer surveillance
- Drug toxicity monitoring
Prognosis
Prognosis depends on disease severity, treatment response, and underlying malignancy. Early diagnosis and cancer treatment improve survival.
Frequently Asked Questions
1. What is dermatomyositis?
Inflammatory muscle disease with characteristic skin rash.
2. What is a shawl sign?
Photosensitive rash over shoulders and upper back.
3. What muscles are affected?
Mainly proximal muscles.
4. Is dysphagia common?
Yes, due to pharyngeal muscle involvement.
5. Why screen for cancer?
Strong association with malignancy.
6. Which cancer is commonly associated?
Lung, ovarian, gastric and others.
7. What is CK?
A marker of muscle injury.
8. What is Gottron papule?
Violaceous papules over knuckles.
9. What is heliotrope rash?
Purple discoloration around eyelids.
10. Can dermatomyositis cause respiratory failure?
Yes.
11. Is biopsy useful?
Yes, for diagnosis confirmation.
12. What is first-line treatment?
Glucocorticoids.
13. Can symptoms improve?
Often improve with therapy.
14. Is physiotherapy important?
Yes, for functional recovery.
15. What determines prognosis?
Malignancy status and treatment response.
References
- Harrison's Principles of Internal Medicine
- Oxford Handbook of Clinical Medicine
- ACP Medicine
- EULAR Recommendations
- UpToDate Review Articles