Question
A 26 year old woman presents with fever, arthralgia and erythema nodosum. Her chest X-ray reveals bilateral hilar lymphadenopathy. Her mantoux test is negative. The most likely diagnosis is:
| A. |
Tuberculosis
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| B. |
Allergic bronchopulmonary aspergillosis
|
| C. |
Sarcoidosis
|
| D. |
Pulmonary thromboembolism
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Show Answer
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Correct Answer � C
Explanation
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|
Sarcoidosis is a systemic granulomatous disorder of unknown etiology, characterized by non-caseating granulomas that predominantly affect the lungs and intrathoracic lymph nodes.
Classic Triad of Löfgren’s Syndrome (Acute Sarcoidosis):
- Fever
- Erythema nodosum (painful red nodules on the shins)
- Bilateral hilar lymphadenopathy (BHL)
Arthralgia/polyarthritis (often ankles) is also common in young females.
Key Diagnostic Clues in This Case:
-
Bilateral hilar lymphadenopathy (BHL) on CXR:
- Strongly associated with sarcoidosis, especially when accompanied by systemic symptoms like fever and arthralgia.
-
Erythema nodosum (EN):
- A classic cutaneous manifestation of sarcoidosis, especially in young women.
- Represents a good prognostic indicator in sarcoidosis.
-
Negative Mantoux test (Tuberculin skin test):
- In sarcoidosis, there is anergy due to T-cell dysfunction, resulting in a negative Mantoux test despite granulomatous inflammation.
Other Supporting Findings in Sarcoidosis:
- Hypercalcemia/hypercalciuria (due to increased 1α-hydroxylase activity in granulomas).
- Elevated serum angiotensin-converting enzyme (ACE).
- Restrictive lung pattern with reduced DLCO on PFTs.
Why Not the Other Options:
