Cryoanalgesia for post-herpetic neuralgia: a new treatment.

The existent therapeutic options for post-herpetic neuralgia (PHN) are varied, albeit not sufficiently effective. The aim of this study was to try a new treatment modality for PHN. A spray of liquid nitrogen (LN) was used in 47 patients suffering from PHN as a stimulator of a mechanism not yet completely understood. The LN spray was carefully applied (so as not to freeze the skin surface) along the diseased sensory nerve dermatome, at weekly sessions lasting for 30 seconds each, with a mean of three applications per patient. The area corresponding to the dermatomes affected by the herpes zoster satisfactorily attenuated the herpetic neuralgia in all patients. Before the sixth treatment session, good or excellent improvement was obtained in 94% of the study patients. Pain was eliminated with one session in nine patients (19%), and with two sessions in eight patients (17%). We conclude that this non-freezing technique is absolutely safe and injury-free, and is very efficient in calming PHN.