Pilot use of a mycolactone-specific lateral flow assay for Buruli ulcer: A case report from Japan

•A Japanese girl developed Buruli ulcer (BU) with edema on the left forearm.•A mycolactone-specific lateral flow assay prototype was used as a point-of-care test.•The prototype test was performed on different lesion sites for clinical course follow-up.•The prototype test yielded positive results in the advancing necrotic area.•Potential test for diagnosis, lesion spread predictions, and assessment of cure. Buruli ulcer, caused by Mycobacterium (M.) ulcerans, is a neglected tropical disease (NTD) characterized by necrosis of the cutaneous tissue, predominantly affecting the limbs. The pathogenesis of this disease is mainly attributed to mycolactone, a lipid toxin produced by M. ulcerans. Here, we report the case of a 7-year-old Japanese girl who presented with worsening ulceration on her left forearm, extending to the elbow, following antimicrobial treatment. To evaluate disease progression, we used a mycolactone-specific lateral flow assay. The test yielded positive results in the advancing necrotic area, aiding in determining the extent of necessary debridement. After undergoing two debridement surgeries and receiving 38 weeks of antimicrobial treatment followed by skin grafting, the patient achieved cure. Timely diagnosis is imperative in avoiding prolonged treatment, highlighting the importance of readily available diagnostic point-of-care tests for Buruli ulcer. Moreover, detection of mycolactone not only can serve as a diagnostic tool for Buruli ulcer but also enables prediction of lesion spread and assessment of cure.