A device for the treatment of rhinitis by biostimulative illumination. The device comprises a pair of LEDs (504a; 505b) containing probes (202a; 202b) adapted to be inserted into the nostrils of a patient. A probes support casing (204), the probes being normally flexibly attracted one against the other. The casing accommodates an electric power source (502), an ON/OFF normally open micro-switch (504a) and circuit means for activating/deactivating the LEDs (504a; 504b). The casing (204) is made of at least partly elastomeric material whereby the micro-switch (504a) becomes activated by pressing against a side-wing (206a) of the casing also causing the probes to spread apart from each other and the micro-switch remains closed for as long as the probes are kept apart from each other.