title: Using oral medications, infusions and injections for differential diagnosis of orofacial pain.
abstract: Chronic orofacial pain is a rapidly evolving and challenging field that deals with the management of pain originating from neurogenic, osseous, muscular, or vascular structures of the head and neck. The challenge lies in the accurate diagnosis of orofacial pain conditions, which may be difficult to differentiate in many clinical situations. As pain cannot be "seen" or precisely located or its intensity measured with any device, clinicians must rely heavily on the patient's own description of type, duration and location of pain, and thus, history plays a crucial role in diagnosis. Advances in neuroscience, pharmacology, and pain management have made medications one of the primary therapeutic modalities in the management of pain including orofacial pain conditions. Despite this, these medications will not help patients if the origin and nature of pain is not accurately diagnosed. Hence, diagnosis is critical for successful management of orofacial pain conditions. Experience and knowledge of practice in pain management have led clinicians to devise several clinical diagnostic tests using medications in various forms (topical, oral, injections, intravenous infusions) to differentiate certain orofacial pain disorders where the nature of pain is unclear and the presentation of pain is at multiple sites. Although the diagnostic tests are not 100 percent accurate, they are very effective in many clinical scenarios, especially in orofacial pain conditions. Topical medications such as anesthetics and anti-inflammatories, oral medications such as anti-inflammatory drugs and skeletal muscle relaxants, injections such as local anesthetics and corticosteroids, and vapocoolant sprays are some examples of the modalities used by clinicians to manage orofacial pain conditions. These medications may also be used for diagnostic tests to aid in accurate diagnosis of some orofacial pain conditions. In addition, there are special cases where medications such as triptans, carbamazepine and indomethacin may be used as diagnostic tests to confirm diagnosis of migraines, neuralgias, or stabbing headaches, respectively. Based on the concept of using medications to predict which treatment would be best for certain pain conditions or to aid in better diagnosis, diagnostic intravenous infusions of lidocaine, morphine, and ketamine have been studied to test the response to adjuvant analgesics and oral dextromethorphan. Paradoxically, taking the patients off their current medications can be of diagnostic significance in conditions like medication overuse headache and serotonin selective reuptake inhibitor-induced clenching. In summary, this paper focuses on the use of medications in different forms as useful diagnostic tests for differential diagnosis of orofacial pain conditions that are difficult to diagnose or are refractory to past or current treatment.
authors.affiliation: Orofacial Pain and Oral Medicine Center, University of Southern California School of Dentistry, Los Angeles 90089, USA.
authors.forename: Saravanan
authors.initials: S
authors.lastname: Ram
authors.forename: Satish K S
authors.initials: SK
authors.lastname: Kumar
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Clark
mesh_terms: D000305:Adrenal Cortex Hormones; D000700:Analgesics; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D000894:Anti-Inflammatory Agents, Non-Steroidal; D003937:Diagnosis, Differential; D005157:Facial Pain / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology; D006801:Humans; D009209:Myofascial Pain Syndromes / Q000188:drug therapy / Q000209:etiology; D009465:Neuromuscular Agents
chemical_list: D000305:Adrenal Cortex Hormones; D000700:Analgesics; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D000894:Anti-Inflammatory Agents, Non-Steroidal; D009465:Neuromuscular Agents