Clinical diagnosis of fluorosis is challenging and requires multidisciplinary collaboration (appendix). Clinicians in migrant-receiving nations often lack awareness of, and available diagnostic tests for, fluorosis, which probably leads to under-reporting. No treatment exists for fluorosis other than halting exposure, with symptom resolution as fluoride mobilises slowly from bone.⁸ The patient’s symptoms markedly improved with reduced pain and with improved mobility and daily activity over the subsequent 9 months after diagnosis, nearly 2 years after fluoride exposure cessation.

Here we have presented a single case of severe skeletal fluorosis; however, entire populations, such as Kakuma’s approximately 185,000 residents, who depend on naturally occurring fluoride-contaminated well water, might be affected en masse.^2,3,4 Many countries with naturally high water-fluoride concentrations host large refugee populations, including Ethiopia, Iraq, Kenya, South Sudan, Syria, and Turkey.^4,7,10 Displaced populations who depend on well water in these areas can be at particular risk, especially children with developing skeletons and lower volumes of distribution. We relayed our clinical information to the Kakuma refugee camp UNHCR Water, Sanitation, and Hygiene officers, who subsequently successfully drilled three new water wells with safe fluoride concentrations (<1·5 mg/L) for the first time.^3,4 Boreholes 13, 14, and 15 produced well water with fluoride concentrations of 1·1 mg/L, 0·9 mg/L, and 0·6 mg/L, respectively (personal communication; Paul Bauman, Advisian, Worley Parsons Group).

The prevalence of skeletal fluorosis in Kakuma could be under-reported. As the numbers of forcefully displaced persons rise globally,¹⁰ clinicians in refugee host nations should maintain a broad approach to newcomers’ health issues and consider potentially important environmental exposures in addition to infectious pathogens. Ultimately, safe drinking water endures as a fundamental principle of human health.

We declare no competing interests. There was no direct funding source for this study. Academic support for GEF and GAK is provided by the Cumming School of Medicine, O’Brien Institute for Public Health, and the W21C Research and Innovation Centre at the University of Calgary and Alberta Health Services. We thank the health-care providers, staff, and patients at the Mosaic Refugee Health Clinic and the institutional support provided by the O’Brien Institute for Public Health and the W21C Research and Innovation Centre at the University of Calgary Cumming School of Medicine— in particular, Garielle Brown for her efforts, without which this report would not be possible. The patient provided written consent for use and disclosure of all relevant clinical information presented.