[Orphan disease of the nose and paranasal sinuses].

Rare rhinological diseases are a diagnostic challenge. From the primary manifestation until the final diagnosis it may take several months or even up to years in which the disease progress is uncontrolled and the disease insufficiently treated. This results in (irreversible) damage and possibly life-threatening situations. The unexpected course of a (misdiagnosed) disease should lead to further diagnostic considerations and steps to detect the orphan disease at a stage as early as possible. In the present work granulomatous diseases of the nose and sinuses caused by mycobacteria, treponemes, klebsiella, fungi and protozoa as well as vasculitis, sarcoidosis, rosacea, the cocaine-induced midline destruction, the nasal extranodal NK/T-cell lymphoma and cholesterol granuloma are discussed. Furthermore diseases with disorders of mucociliary clearance as the primary ciliary dyskinesia and cystic fibrosis are presented taking into account the current literature.