Non-allergic, mastocytosis-associated rhinitis

Systemic mastocytosis (SM) is a clonal proliferative disorder of mast cells (MC) that causes pathological accumulation of mast cells in various tissues, which results in clinical symptoms (e.g. diarrhoea, urticaria) due to MC mediator release. Previous studies have shown that up to fifty percent of rhinitis symptoms in SM patients are non-allergic and it has been assumed that these nasal complaints in SM patients are due an increased nasal mast cell burden. Nevertheless, to date there are no data supporting this hypothesis.

The study aims to investigate if the presence of allergy-suggesting nasal complaints in non-allergic SM patients is correlated with objective measure of nasal mast cell burden.

Eleven adult patients with systemic mastocytosis underwent a comprehensive rhinologic work-up. All patients fulfilled the clinical ARIA criteria for rhinitis. The allergologic work-up included serological allergy testing, determination of tryptase levels (serum and nasal secretion), skin prick testing, and nasal provocation testing.

Ten out of eleven SM patients with clinical persistent allergic rhinitis were found to be non-allergic. In these patients, the most predominant symptoms were rhinorrhea, sneezing, and itching. All three symptoms were strongly correlated with the nasal tryptase level but not to the level of serum tryptase.

Non-allergic persistent nasal complaints in systemic mastocytosis were significantly correlated with elevated nasal tryptase level as a measure of local MC burden. Furthermore, elevated nasal tryptase correlated with persistent rhinorrhea, sneezing, and itching as predominant symptoms, which seems to characterize a non-allergic mastocytosis-associated rhinitis (NAMAR) in systemic mastocytosis.