Relapsing polychondritis — SAQ

Stem

A 52-year-old woman has a second episode of painful erythema and swelling of both cartilaginous pinnae with lobule sparing. She also has nasal-bridge tenderness and new hoarseness. CRP is elevated. There has been no piercing or trauma and there is no abscess.[1][3]

Questions

a) State the leading diagnosis and interpret lobule sparing. (3 marks)[1]

b) Name the three historical diagnostic frameworks and state one important limitation of them. (3 marks)[4][5][6]

c) What complication must be excluded because of hoarseness, and how should it be assessed and managed? (5 marks)[7][8]

d) Give two principles of anti-inflammatory treatment, including the evidence limitation. (2 marks)[2][3]

e) In a man with later-onset disease, fever and macrocytic anaemia, what alternative must be considered and how is the marrow-vacuole clue used correctly? (2 marks)[9][10]

Total: 15 marks[1]

Model Answer and Marking Guide

a) Diagnosis and lobule sign — 3 marks

• Relapsing polychondritis is the leading diagnosis. (1 mark)[1]
• Lobule sparing localises inflammation to the cartilaginous pinna, because the lobule has no cartilage. (1 mark)[1]
• It is a clue, not a specific test: infectious auricular perichondritis can also spare the lobule, while pinna cellulitis more often involves it. (1 mark)[1][3]

b) Historical frameworks — 3 marks

• McAdam. (0.5 mark)[4]
• Damiani–Levine. (0.5 mark)[5]
• Michet. (0.5 mark)[6]
• These are historical aids that are not a prospectively validated gold standard; diagnosis still requires clinical pattern recognition, longitudinal review and exclusion of mimics. (1.5 marks)[1][3]

c) Airway complication — 5 marks

• Exclude laryngeal and tracheobronchial chondritis causing fixed stenosis or dynamic collapse. (1 mark)[8]
• Look immediately for stridor, respiratory distress, hypoxaemia, exhaustion or rapidly progressive symptoms. (0.5 mark)[8]
• If unstable, begin ABC stabilisation and summon senior anaesthesia, ENT, respiratory and ICU teams; prepare expert difficult-airway control and do not delay it for imaging. (1.5 marks)[3][8]
• If stable, arrange airway CT including the cervical trachea and chest with inspiratory and dynamic expiratory acquisitions, plus pulmonary-function tests/flow-volume loops; ENT laryngoscopy is symptom- and expertise-directed. (1.5 marks)[7][8]
• Bronchoscopy is reserved for selected expert indications after risk–benefit assessment because instrumentation can worsen airway injury, bronchospasm or respiratory failure. (0.5 mark)[8]

d) Treatment principles — 2 marks

• Match treatment to severity: mild ear/nose/joint disease may use an NSAID, colchicine or short glucocorticoid course after infection is excluded; organ-threatening disease usually requires systemic glucocorticoids and specialist steroid-sparing therapy. (1 mark)[3][11]
• Explain that treatment is empirical: the systematic review found no randomised controlled trial and pooled only heterogeneous observational reports, so there is no universal dose ladder or proven biologic hierarchy. (1 mark)[2]

e) VEXAS branch — 2 marks

• Consider VEXAS syndrome caused by a somatic UBA1 variant; later onset in a man with fever, macrocytosis/cytopenias, skin or pulmonary inflammation strengthens suspicion. (1 mark)[9][10]
• Vacuoles are sought in bone-marrow myeloid and erythroid precursor cells, not claimed from a routine peripheral-blood film. They support suspicion but do not prove VEXAS; confirm with somatic UBA1 testing. (1 mark)[9][10]

Examiner Pitfalls

• Award no specificity claim for lobule sparing: it does not distinguish RP from every infection.[1][3]
• A candidate who sends an unstable patient to CT before airway stabilisation has missed the life threat.[3][8]
• “Vacuoles on blood film” is incorrect; the characteristic morphology is in marrow precursor cells.[9][10]
• Do not reward a rigid biologic hierarchy or a universal steroid dose as trial-proven RP care.[2][11]

References

1. [1]Mertz P, Costedoat-Chalumeau N, Ferrada MA, et al. Relapsing polychondritis: clinical updates and new differential diagnoses Nat Rev Rheumatol, 2024.PMID 38698240
2. [2]Petitdemange A, Sztejkowski C, Damian L, et al. Treatment of relapsing polychondritis: a systematic review Clin Exp Rheumatol, 2022.PMID 35238756
3. [3]Arnaud L, Costedoat-Chalumeau N, Mathian A, et al. French practical guidelines for the diagnosis and management of relapsing polychondritis Rev Med Interne, 2023.PMID 37236870
4. [4]McAdam LP, O'Hanlan MA, Bluestone R, et al. Relapsing polychondritis: prospective study of 23 patients and a review of the literature Medicine (Baltimore), 1976.PMID 775252
5. [5]Damiani JM, Levine HL Relapsing polychondritis--report of ten cases Laryngoscope, 1979.PMID 449538
6. [6]Michet CJ Jr, McKenna CH, Luthra HS, et al. Relapsing polychondritis. Survival and predictive role of early disease manifestations Ann Intern Med, 1986.PMID 3484422
7. [7]Lee KS, Ernst A, Trentham DE, et al. Relapsing polychondritis: prevalence of expiratory CT airway abnormalities Radiology, 2006.PMID 16801364
8. [8]de Montmollin N, Dusser D, Lorut C, et al. Tracheobronchial involvement of relapsing polychondritis Autoimmun Rev, 2019.PMID 31323366
9. [9]Beck DB, Ferrada MA, Sikora KA, et al. Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease N Engl J Med, 2020.PMID 33108101
10. [10]Ferrada MA, Sikora KA, Luo Y, et al. Somatic Mutations in UBA1 Define a Distinct Subset of Relapsing Polychondritis Patients With VEXAS Arthritis Rheumatol, 2021.PMID 33779074
11. [11]Borgia F, Giuffrida R, Guarneri F, et al. Relapsing Polychondritis: An Updated Review Biomedicines, 2018.PMID 30072598