Get bad acne on my shoulders when I sunbathe

I don't really suffer from acne normally. The only time I get it is when I sunbathe. The strange thing is that it only affects my shoulders. I get between 5 and maybe 20 yellow spots on the top of my shoulders (and maybe one or two on my upper chest). It happens if I use suncream (tried high and low factors) and if I am out for even half an hour without suncream so I do not think it is an allergic reaction to the cream.

Anyone else suffered with this. What can I do to help it?

Thanks in advance for your responses.

[loiloi]

Suncreams tend to be greasy so may lead to spots. It might be better to cover your shoulders rather than apply lotion to these areas. It also sounds as if you are sensitive to the sun and should avoid sunbeds and too much sun exposure at the hottest times of the day.