Early treatment of capsaicin-induced dermal pain with the use of topical antacids can be effective in quickly and significantly reducing skin irritation and discomfort, according to a recent study.
"Dermal exposure of capsaicin affects cutaneous sensory neurons, inducing burning, redness, irritation, and pain that sometimes can be excruciating and last for hours to days after exposure," wrote Susan Y. Kim-Katz, Pharm.D., and her associates.
However, the results of their study, published online in the American Journal of Emergency Medicine, suggested the pain can be alleviated within 30 minutes if treated with an antacid containing calcium or magnesium.
Participants in the study were recruited from the California Poison Control System (CPCS) 24-hour hotline from a pool of callers who reported dermal exposure to capsaicin over the 15-month period between January 2001 and April 2002. In addition, study participants contacted the CPCS a median of 1 hour after exposure.
In the 64 subjects whose data were analyzed for outcomes, 45 (70%) reported a positive response to antacid treatment as a 33% reduction in pain within 30 minutes, noted Dr. Kim-Katz, a clinical pharmacist at the University of California, San Francisco.
A majority of participants, 36 (56%), were exposed to unrefined capsaicin through natural peppers (such as jalapeño, habañero, or red chili), while the remaining subjects were exposed to refined capsaicin (as contained in personal protection sprays such as pepper spray, animal repellents, creams, or ointments). They were advised by the CPCS to coat or soak the affected area liberally with a room-temperature antacid product that contains calcium or magnesium, such as Maalox, Mylanta, Milk of Magnesia, or Tums (crushed and mixed with water).
When asked to assess their pain on a scale of 0 (no pain) to 10 (worst pain ever experienced) during the initial phone call to CPCS, the median initial pain score was 7.5. During a follow-up call 2 hours after the initial CPCS consultation, the mean decrease in pain score after treatment was 4.2 points (doi:10.1016/j.ajcm.2009.02.007).
The study's authors discussed similar studies that have supported this outcome, including a 1998 study. In that study, seven patients had "severe dermal discomfort" after "pepper-mace" exposure. Within minutes after they applied liquid Maalox to the affected area, the patients were pain free (Am. J. Emerg. Med. 1998;16:613-4).
Topical antacids may provide pain relief by raising extracellular pH, which decreases skin pain receptors' sensitivity to capsaicin, the researchers said. In addition, the presence of positively charged calcium and magnesium atoms in the antacid may suppress capsaicin's actions, they noted.
Organic "red hot chili peppers" from Hutchins Farm in Concord, Mass. (Image courtesy "Arden" via flickr creative commons)
Dr. Kim-Katz and several of her colleagues reported that they are on staff at the California Poison Control System, San Francisco Division.