Diagnosis and Assessment of Disease
ÎDifferentiating HZ from Herpes simplex virus (HSV) infection is difficult; HZ should be diagnosed using laboratory diagnostic testing.
ÎUsually, HSV is found around the mouth and genitals and not on the trunk.
ÎAvailable diagnostic tests include viral culture, immunofluorescence antigen (IFA) or enzyme immunoassay (EIA) antigen detection, PCR, and serology.
Selecting a Treatment Regimen
ÎMedications FDA approved for PHN based upon established efficacy include gabapentin (GBP), pregabalin, topical lidocaine and 8% capsaicin* (newly FDA-approved).
ÎMedications with established efficacy for PHN include tramadol,† tricyclic antidepressants (TCAs), and opioids.
valproate,
ÎDue to excellent tolerability, topical lidocaine may be preferred in older patients, particularly for those with allodynia and a small area of pain.
ÎThere are few data regarding the additive or synergistic benefits of combination treatment.
ÎPatients who require complex drug combinations, risky second-line medications, or invasive treatments should be referred to a pain management center.
ÎInvasive treatments may be considered when patients fail to obtain adequate relief from noninvasive treatment approaches.
> Invasive treatments include peripheral and central neural blockade, central nervous system drug delivery, spinal cord stimulation, and neurosurgical techniques.
* Awareness of this formulation of capsaicin is limited. † Suicide risk increases in addiction-prone patients, as well as those taking antidepressants or tranquilizers.
