When perennial rhinitis worsens: rhinolith mimicking severe allergic rhinitis.

Allergic rhinitis is one of the most common causes of nasal obstruction, but other diseases need to be considered particularly when the clinical course is getting worse. We present a patient with known mild persistent allergic rhinitis due to house dust mites who experienced progressive worsening of nasal obstruction with associated hyposmia and mucopurulent discharge. The lack of improvement of the patient's symptoms prompted the re-evaluation of the case. Skin prick tests for airborne allergens confirmed sensitisation only to house dust mites. Nasal endoscopy and facial CT scan revealed a huge rhinolith occupying almost completely the right nasal cavity. The rhinolith was surgically removed with resolution of symptoms. Rhinoliths are rare and unusual calcified materials which grow around intranasal foreign body; they are often promoted by trauma, surgical operations and dental work. The patient underwent dental work about 30 months before the diagnosis of rhinolith, suggesting a possible aetiology.