Alimemazine and the sun

[Swannykazoo]

Have this on specialist advice from our dermatologist as whilst Little Puggle's (17mnths) eczema isn't bad, he has the most terrible itch and if left without scratch sleeves will claw any exposed skin. I just give a single dose at night if he's very itchy. Obviously if I've accidentally had dairy (chorizo I'm looking at you!) or something with eggs his itch is worse as he's still BF
I've just spotted the advice that it may cause sun sensitivity. Has anyone any experience of this?
We're off to the sun soon, we're not going to go mad with lard in the midday sun but only have short sleeve sun suit....