Touch Lamps & Static Electricity
Electronic devices are subject to damage by electrostatic discharge (ESD). Walking across a carpeted floor can create a potential of 25,000 volts. To estimate the voltage, note how far a spark jumps from a finger to a grounded object, e.g. a wall-switch screw): a rough guide is ~1,000 V/mm or ~25,000 V/inch. 

That said, reputable manufacturers include ESD protection to thousands of volts and high pulse currents in consumer electronics. Though you can protect the device by reducing nearby ESD (using antistatic spray on carpets, room humidifiers, etc.), a well-made capacitance switch should not fail from a small spark. You might try a different brand of touch-control lamp. [The ones I use have lasted through about five years of cold, dry winters with many finger-to-lamp sparks. ouch]