Some studies of high altitude populations argue that stature reduction results from caloric, rather than hypoxic, stress. However, tradeoff models of oxygen and glucose metabolism predict that in hypoxemia, glucose metabolism will be downregulated. We used tradeoff assumptions in two hypotheses: First, that hypoxia targets leg segment growth differentially, and second, that proportions of leg segments partition the impact of high altitude into hypoxemic and energetic components. A group of 113 Han and Tibetan middle school children at 3100 m aged 8 to 11 were measured for segment anthropometries, skinfolds, vital capacity, blood oxygen saturation, and percent body fat. MANOVA showed that Tibetan children were significantly larger and fatter than Han children. Independent of ethnicity or caloric status, absolute and relative tibia length was significantly reduced in children with lower blood oxygen saturation. Height, chest circumference, sitting height, tibia length, and ankle diameter were greatest in fatter children, independent of ethnicity or blood oxygen. For children of either ethnicity with the lowest blood oxygen, size as well as proportion was impacted. These results support the tradeoff model. Caloric reserves and ethnicity independently affect total skeletal size. Oxygen saturation and ethnicity affect leg proportions. In hypoxemia, body fat has less impact on growth than when ample oxygen is present. Therefore, we should qualify the claim that size in high altitude populations stems from nutritional stress. The findings also suggest that decanalization may have different meanings and outcomes depending on which body segments contribute to the effect.

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Dear Editor, A 21-year-old woman presented with a pruritic erythematous area and pustules on her right palm for 5 days (a). She was treated with topical steroids without improvement. Her contact with a pet hedgehog suggested tinea incognito (b). 1 This was confirmed by cultures from the lesion and the pet's quill. Microscopic examination of two slide cultures with fluorescence staining revealed similar teardrop-shaped microconidia along the sides of the hyphae. Scanning electron microscopy of a quill demonstrated dense biofilms of hyphae (c). Trichophyton erinacei (GenBank MN939685 and MT002727) was identified by sequencing. The zoophilic dermatophytes induce marked dermal inflammatory responses, which may lead to misdiagnosis.

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