# Rapid Reversal of Forearm Supinator Rigidity With Topical Isomerized Potassium Linoleate: A Novel Perspective on Microbiome-Induced Tetany

## TL;DR

This paper reports that applying a topical cleanser containing isomerized potassium linoleate rapidly reduced forearm rigidity in patients with no nerve injury, suggesting a role for the skin microbiome in tetany.

## Contribution

The study introduces a novel perspective on how the skin microbiome may contribute to tetany and demonstrates a rapid, non-invasive treatment approach.

## Key findings

- Application of isomerized potassium linoleate resolved forearm supinator tenderness within 2-4 minutes.
- Improved wrist rotation range of motion was observed within 3-10 minutes and lasted beyond the clinic visit.
- No evidence of nerve injury was found in patients, suggesting a non-neurological cause for tetany.

## Abstract

Microbes can alter host behavior, immunity, and neurological function at a distance without extension into the brain and spinal cord. Clostridia provides a predicate for such an infection in the periphery by causing “lock jaw” and generalized tetany. This case series presents five patients who showed rigidity or tetany of the forearm. All were diagnosed with vertigo of central origin by video nystagmography (VNG) and posturography. Each had an apparent slow-rolling tetany, most visible in the forearm. Each had a consistent focus of pain within the supinator, diminution of extended wrist rotation, and tender, taut bands. None had clinical evidence of injury to the ulnar, radial, or median nerves, ulnar epicondyles, or wrist. The author applied a commercial preparation of a cleanser containing isomerized potassium linoleate (KCLA) to the skin overlying the forearm's biceps, supinator, and pronator as an “alternative” medical approach to refractory rigidity and tenderness. The tenderness resolved within two to four minutes. After 3-10 minutes, follow-on extended wrist rotation improved toward the norm (p < 0.01). The improved range of motion lasted beyond discharge from the clinic visit. The rapid response in this series suggests the commensal skin biome may contribute to clinical tetany in the forearm supinator.