Apparatus and methods are disclosed for treating allergic rhinitis (seasonal and perennial hay fever), by application of flash lamp radiation. The nasal cavity can be illuminated in a safe and effective manner, with non-coherent light from a flash-lamp or other suitable source. This illumination can be accomplished in any suitable manner, including by use of a handheld device. Such handheld embodiments may contain a power source (battery or AC), control circuitry, light source (flash-lamp or diode laser), lens (focusing or non-focusing), light filter, and/or fiber-optic for delivering light to the nasal cavity. Embodiments include using any suitable light energy, such as visible light in the red wavelengths with a power output of 1 to 10 Joules per cm2. The device can be pre-programmed to deliver a specified amount of light in a specified amount of time using multiple pulses (in the case of a flash lamp) or a continuous wave (in the case of a diode laser). In many useful embodiments, a rigid fiber-optic extends from the lens/light filter a length of 10 to 20 mm, although it can be any convenient and useful size and shape. Contact sensors can be arrayed on the device for various purposes, such as to restrict illumination to times when the fiber optic is inserted into the nasal cavity. This and/or other safety features can prevent the high-intensity light from being fired into open space, a persons eyes, and/or otherwise causing a potential vision or other hazard. Preferably, the device can be easily and comfortably inserted into a nostril. The fiber-optic can be angled (either in its own shape or by the user manipulating it to a convenient angle/position) so as to allow the user to easily grip the device and insert the fiber-optic without having to use a mirror or other aid. Light from the device can be emitted at a specified light frequency that causes a desired immunosuppressive response in the cellular system.
