By Samuel D. Chumbley
Year 1, Medicine, University of Exeter
Email: sc579@exeter.ac.uk
Since humans first began to consume chilli peppers, the plight of capsaicin-induced proctalgia has been known. Capsaicin-induced proctalgia is the familiar burning sensation one experiences around their anus when passing previously ingested chilli. The sensation is similar to that experienced in the oral mucosa,1 but significantly more painful2 and significantly more taboo to discuss at dinner parties.3
This crippling condition is more well-known by many colloquial names, such as: “Ring of Fire”, “Ring Sting” or “Ghandi’s Revenge”. Although well-known, there are few remedies known to alleviate the symptoms of “Frodo” (the destroyer of the “One Ring” in “The Lord of the Rings”).4
Despite inducing the sensation that one has cleaned their anus with sandpaper, capsaicin, the active burning ingredient of chilli, has been paradoxically used to treat pain.1,5 The activation of transient receptor potential vanilloid 1 (TRPV1; the capsaicin receptor site) can actually desensitise epidermal nerves and, therefore, reduce neuropathic pain. Meanwhile, the shorter-lasting activation of transient receptor potential ankyrin 1 (TRPA1) by capsaicin summons the familiar searing pain that gives new meaning to “bowels of hell”.6
Since pain was an enduring symptom of capsaicin exposure, despite the synergistic desensitisation, research returned to the proverbial drawing board, which may have then been guided by a scientist that abandoned the standard dairy-binge approach and brushed their teeth after a regrettable vindaloo…
Research has since suggested that menthol, the active cooling ingredient in peppermint, can reduce oral sensitisation to capsaicin if locally applied within 15 minutes prior to and five minutes following capsaicin exposure.7 However, if applied outside this therapeutic window, the menthol can actually enhance nociception.7,8 Consequently, it could be concluded that, when experiencing capsaicin-induced proctalgia, one must fetch the ColgateTM, apply liberally, and definitely act quickly!*
*Recommended by 0 in 10 dentists.
Disclaimer This article is intended as light relief and is not serious advice. The author is, therefore, not responsible for any toothpaste-stained clothing.
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References
- Fattori V, Hohmann MSN, Rossaneis AC, Pinho-Ribeiro FA, Verri WAV. Capsaicin: current understanding of its mechanisms and therapy of pain and other pre-clinical and clinical uses. Molecules. 2016; 21(7): 844.
- Personal experience.
- Sadly, another personal experience.
- Tolkien JRR. The Lord of the Rings: Return of the King. 1955; George Allen & Unwin Ltd, London. 1955.
- British National Formulary. Capsaicin. Available from: https://bnf.nice.org.uk/drug/capsaicin.html. Accessed 5 May 2019.
- Spahn V, Stein C, Zoellner C. Modulation of transient receptor vanilloid 1 activity by transient receptor potential ankyrin 1. Mol Pharmacol. 2014; 85(2): 335-344.
- Takaishi M, Uchida K, Tominaga M. Reciprocal effects of capsaicin and menthol on thermosensation through regulated activities of TRPV1 and TRPM8. J Physiol Sci. 2016; 66(2): 143–155.
- Green BG, McAuliffe BL. Menthol desensitization of capsaicin irritation. Evidence of a short-term anti-nociceptive effect. Physiol Behav. 2000; 68(5): 631–639.