Best mosquito repellent for sensitive skin?

[LakeFlyPie]

DS (8) has very sensitive skin, already struggling with suitable suncream (am putting my faith in Ladival). We're travelling to SA (non malarial areas) and could do with some decent repellent that won't irritate his skin. Tried Smidge last year and he complained that it stung. Any suggestions / advice would be gratefully received.
TIA

Avon skin so soft has a weird reputation for being mosquito repellent.

Took the Avon skin so soft to Costa Rica as I'm not a fan of chemicals - after 2 days of getting bitten , I switched to deet! My DD has very sensitive skin too and I used Ben's Family Insect Repellent on her which worked and she had no problems with. It does contain deet though!

ps - you can get it from chemist.co.uk as I've just re-ordered some!

Thanks, may try both!