What is Rhinitis Caseosa?
Rhinitis caseosa is a rare chronic inflammatory condition characterized by the accumulation of foul-smelling, cheese-like (caseous) material within the nasal cavity or paranasal sinuses, often associated with nasal obstruction and polyposis. 1, 2
Clinical Characteristics
Key presenting features include:
- Nasal obstruction is the universal presenting symptom in all reported cases 1, 2
- Nasal polyposis accompanies the caseous material accumulation 2
- Foul-smelling discharge from the characteristic cheese-like debris 1
- Unilateral or bilateral involvement of the nasal cavity and/or maxillary sinuses 1
The condition can manifest as isolated rhinitis caseosa (nasal cavity only), maxillary sinusitis caseosa (sinus only), or combined involvement of both sites 1.
Relationship to Other Conditions
Rhinitis caseosa shares striking clinical, radiological, and histological similarities with allergic fungal sinusitis (AFS), though a fungal etiology is confirmed in only a minority of cases 2. The condition is also referred to as "nasal cholesteatoma" in older literature, reflecting the caseous nature of the accumulated material 2.
Despite these similarities to AFS, most cases do not demonstrate fungal involvement on microbiologic examination, suggesting rhinitis caseosa may represent an "AFS-like syndrome" with a different underlying pathophysiology 2.
Diagnostic Findings
CT imaging may reveal:
- Intracranial extension in approximately one-third of cases 2
- Intra-orbital extension in approximately one-third of cases 2
- Sinus opacification with characteristic caseous material 1
These imaging findings underscore the potentially aggressive nature of this condition and the importance of thorough radiological evaluation 2.
Treatment Approach
Surgical debridement with establishment of adequate sinus drainage is the definitive treatment, with excellent long-term outcomes 1, 2. Specific surgical techniques include:
- Transmaxillary sinus microsurgery for maxillary sinus involvement 1
- Middle meatal antrostomy to ensure free drainage of the sinus ostium 1
- Complete removal of caseous material and diseased tissue 2
The critical surgical principle is ensuring free drainage of the sinus ostium, which prevents recurrence 1. Long-term follow-up data demonstrate that 26 of 28 patients (93%) remained recurrence-free for at least one year following appropriate surgical intervention 2.
Clinical Pitfalls
Do not confuse rhinitis caseosa with:
- Standard chronic rhinosinusitis, which lacks the characteristic caseous material accumulation 3, 4
- Allergic fungal sinusitis, though overlap exists and fungal cultures should still be obtained 2
- Atrophic rhinitis, which presents with crusting but different pathophysiology 3
The "silent" nature of some presentations (minimal pain despite extensive disease) can lead to delayed diagnosis, particularly when intracranial or orbital extension has occurred 2.