Children’s head circumference and other stories . . .

Most GPs and paediatricians have a tape measure in their top drawer that they bring out regularly to measure head circumference. A study of 10 851 children with more than two head measurements from the Avon Longitudinal Study of Parents and Children, based in Bristol, finds that centile shifts within the normal range are common and mainly reflect measurement error (Pediatrics 2015, doi:10.1542/peds.2014-3172). The investigators found that abnormalities of head size are neither specific nor sensitive for detecting neurocognitive disorders, “suggesting that routine measurement of head circumference is unhelpful.” Perhaps the main function of that tape measure is just to transfer the scalp flora of one baby to another.

Most British gardens used to contain the tracks of hedgehogs. But while they are sadly becoming a rarity on the ground, hedgehog pathways have become popular in cancer pharmacology. This ancient cellular signalling system can be inhibited by many drugs, from arsenic to a new …