Smartphones have been blamed for a dramatic rise in head lice among schoolchildren because they encourage youngsters to gather round in groups, allowing the bugs to jump between heads.

A study of more than 200 youngsters found those owning a smartphone - or tablet - were more than twice as likely to be infested with lice.

Out of the 98 who did not have or use either type of device 29 (29.5 per cent) experienced head lice - compared to 65 of the 104 (62.5 per cent) who did.

Almost half of the participants had lice at some point in the previous five years, up to 22 times more than the figure of two to eight percent that has been calculated in the past.

However taking regular selfies was not a major factor in the rise contrary to previous suggestions.

In 2015, Wisconsin GP Sharon Rink coined the phrase 'social media lice', claiming the upsurge in head lice was caused by group selfies, which caused friends to bump heads.