Posttraumatic and Postsurgical Neuropathic Pain Responsive to Treatment with Capsaicin 8% Topical Patch

Capsaicin 8% patch (Qutenza) is mainly used to treat postherpetic neuralgia and human immunodeficiency virus-associated neuropathy. However, evidence of the efficacy of Qutenza in other forms of neuropathic pain is lacking. A 24-year old Libyan man, with no previous medical history, sustained multiple wounds in the right side of the chest and back after a bomb explosion. The patient experienced pain, which persisted in a wide location around the surgical intervention for a long time, beyond the usual course of natural healing of an acute pain and was different from that suffered preoperatively. The characteristics of the pain included burning, electric shock-like sensation, tingling, and numbness, and it was paroxysmal. The pain was associated with hyperalgesia and intense allodynia in a wide area, approximately of 1,100 cm2. Our initial treatment strategy included pregabalin, tramadol, and duloxetine. However, our patient's pain responded to treatment with capsaicin 8% patch when the initial treatments showed only minimal effectiveness regarding the intensity of pain. Interestingly, the most important finding was that capsaicin 8% patch showed a more than 80% reduction of the area of allodynia associated with the pain, when other treatments failed. Moreover, although recent data showed that in patients who respond to Qutenza, analgesia starts within a few days of treatment and lasts on average 5 months, our patient showed an initial response within 7 days of treatment but a longer duration of more than 18 months. Although further controlled studies are needed to explore the efficacy of the capsaicin 8% patch in patients who experience posttraumatic neuropathic pain, we encourage clinicians to try the capsaicin 8% patch when alternative treatments fail.