relapsing polychondritis

Relapsing polychondritis is a rare multi-systemic disease characterized by recurrent inflammation of cartilaginous structures in the body. It can also affect other proteoglycan-rich structures .

Epidemiology

The condition is extremely rare with an estimated incidence of ~1 in 285,000. There is no recognized gender predilection although pulmonary involvement may be more common in females . Patients typically present in middle age and there is equal occurrence in men and women .

Clinical presentation

Respiratory symptoms are seen in ~20% of patients at presentation and eventually ~60% will develop respiratory tract involvement which is manifested by a combination of symptoms including laryngeal tenderness, hoarseness, dyspnea, and stridor/wheeze.

Pathology

An autoimmune mediated mechanism has been postulated.

Location

Commonly affected areas include:

• tracheobronchial tree: present in up to 50% of cases
• external ear cartilages
• nasal cartilages
• peripheral joints
• laryngeal cartilages 

Other areas that can be involved include :

• uvea: uveal inflammation
• cardiovascular system: aortitis/arteritis

Radiographic features

CT

In the chest:

• increased airway wall attenuation: common
• smooth anterior and lateral tracheal wall thickening with sparing of the posterior membranous wall: if present is considered virtually pathognomonic
• luminal narrowing: tracheobronchial and peripheralbronchial
• accompanying dense tracheal cartilage calcification
• sub-glottic stenosis
• dynamic imaging may demonstrate airway collapse best seen at end expiratory phase (dynamic tracheal collapse)
• lobar air trapping 
• bronchiectasis: uncommon 
• lymphadenopathy is generally not a feature but may be present in some cases

Treatment and prognosis 

Many patients have a fluctuating but progressive course. Most morbidity and mortality is due to respiratory involvement (frequent respiratory infection and airway collapse). Medical management (with corticosteroids, NSAIDs, azathioprine, cyclosporin) is the mainstay of treatment. Selected surgical options include :

• tracheostomy: for localized upper airway involvement
• endobronchial polymeric silicone stent placement to aid/maintain airway patency

Differential diagnosis

The differential will somewhat depend on the spectrum of organ involvement.

For tracheal and bronchial thickening consider:

• tracheobronchopathia osteochondroplastica
  • also spares the posterior membranous portions
  • thickening is irregular and nodular
• tracheobronchial amyloidosis
  • circumferential involvement

For tracheal narrowing consider: differential of diffuse tracheal narrowing

Siehe auch:

• Trachealstenose
• diffuse Trachealverengung
• Differenzialdiagnosen bei Tracheomalazie
• tracheobronchiale Chondritis
• Chondritis der Rippen

und weiter:

• Sakroiliitis
• diffuse Trachealwandverdickung
• Tracheobronchopathica osteochondroplastica (TBO)
• Amyloidose des Tracheobronchialsystem
• Knorpelentzündung
• Chondritis des Larynx