Acute mountain sickness in children and adolescents Gaurav Sikri, Armed Forces Medical College Pune India 4 August 2015 I read with great interest the article “The impact of physical fitness and body mass index in children on the development of acute mountain sickness: A prospective observational study” by Wu et al . Major strength of this work is that it has studied the incidence of acute mountain sickness (AMS) and its relationship with physical fitness and body mass index (BMI) amongst children and adolescents. The authors have reported overall incidence of AMS as 44.7% (80 out of 179 subjects). They have also observed the incidence of AMS as 6.1% on night 1, 31.5% on night 2 and 27% after summit on day3. It is also mentioned in the article that 14 subjects (11 out of 14 had AMS) could not complete their ascent to Xue mountain but were included in the analysis. As a reader I was interested in knowing that whether these 11 children were the same subjects who were diagnosed as AMS on night 1at Qika hut (6.1% of 179) or not. Moreover, AMS patients, who were prescribed drugs like acetaminophen and acetazolamide, were they excluded from the study group or they still continued to be a part of the study after resolution of the symptoms. If they were allowed to ascend, use of drugs especially acetazolamide would have a bearing on the reported incidence of AMS. AMS is known to occur within 6-12 hours after the exposure to high altitude and its incidence rises with increasing altitude [2-4]. On day3, after 5 hours of ascent to the summit of Xue Mountain (3886 m) and possibly a brief stay there, the subjects returned to Sanliujian Hut (3154 m) after varying time depending on their physical fitness. They were examined actually at an altitude of 3154m (732 m lower than the summit) over a period of time (say few hours). Authors have acknowledged that each group departed one day apart from the previous group due to limited maximal capacity at the Qika and Sanliujiu huts. Being a physiologist working in high altitude medicine research, I was interested in knowing the number of children in each of the groups and number of trained physicians who carried out the physical examination at Sanliuijian hut. The time lag between the actual exposure to altitude and the physical examination is likely to affect the incidence of AMS in subjects of all the four fitness groups. References: Wu SH, Lin YC, Weng YM, Chiu YH, Li WC, Wang SH, et al. The impact of physical fitness and body mass index in children on the development of acute mountain sickness: A prospective observational study. BMC Pediatrics.2015; 15:55. Burtscher M, Wille M, Menz V, Faulhaber M, and Gatterer H. Symptom progression in acute mountain sickness (AMS) during a 12-hour exposure to normobaric hypoxia equivalent to 4500 m. High Alt Med Biol. 2014;15:446–451. Pollard AJ, Niermeyer S, Barry P, Bärtsch P, Berghold F, Bishop RA, et al.Children at high altitude: an international consensus statement by an adhoc committee of the International Society for Mountain Medicine, March12, 2001. High Alt Med Biol. 2001; 2(3):389–403. Roach RC, Hackett PH. Frontiers of hypoxia research: acute mountain sickness. J Exp Biol. 2001; 204: 3161–70. Competing interests There are no competing interests.