Topical treatments of skin pain: a general review with a focus on hidradenitis suppurativa with topical agents.

Hidradenitis Supprurativa (HS) is a painful chronic follicular disease. Few papers have addressed pain control for this debilitating condition. Possible topical agents include tricyclic antidepressants, opioids, anticonvulsants, NSAIDs, NMDA receptor antagonists, local anesthetics and other agents. The first line agents for the topical treatment of the cutaneous pain of HS are diclonefac gel 1% and liposomal xylocaine 4% and 5% cream or 5% ointment. The chief advantage of topical xylocaine is that is quick acting i.e. immediate however with a limited duration of effect 1-2 hours. The use of topical ketamine, which blocks n-methyl-D-aspartate receptors in a non-competitive fashion, might be a useful tool for the treatment of HS pain. Topical doxepin, which available in a 5% commercially preparation (Zonalon®) , makes patients drowsy and is not useful for controlling the pain of HS . Doxepin is available in a 3% or 3.3% concentration (which causes less drowsiness) from compounding pharmacies and can be used in compounded analgesic preparations with positive effect. Topical doxepin is preferred over use of topical amitriptyline because topical doxepin is more effective. Nevertheless, topical amitriptyline increase of the tactile and mechanical nociceptive thresholds and can be used for topical pain control in compound mixture of analgesics . Gabapentin and pregablin can also be used compounded with other agents in topical analgesic preparations with positive topical anesthetic effect. Capsaicin is not useful for topical treatment of the pain of HS. Sometimes compounded of anesthetics medications such as ketamine 10%, bupivacaine 1%, diclofenac 3%, doxepin 3% or 3.3%, and gabapentin 6% can extend the duration of effect so that medication only needs to be used 2 or 3 times a day. Still in my experience the easiest to get and most patient requested agent is topical diclonefac 1% gel.