A low-dose capsaicin nasal spray — or pepper spray — that can be self-administered once daily for idiopathic rhinitis works as well as a higher dose one administered over several hours in hospital with local anaesthetic, a new study suggests.

Researchers compared two different concentrations of capsaicin nasal spray (0.01 millimolar and 0.001 mM) self-administered once daily at home as well as the current standard of care for idiopathic rhinitis of capsaicin which is delivered in hospital.

This consists of five consecutive applications of 0.1 mM capsaicin administered with local anaesthetic at one-hour intervals.

Patients assigned to standard care received high-dose capsaicin in the hospital with local anaesthetic, then were sent home to self-administer a placebo nasal spray for four weeks.