Why do I get a rash after taking Nyquil?

So in the last few months I've taken Nyquil Cold & Flu Nighttime Relief (liquid) about 3 times, the first time my face broke out in a weird rash or some sort of hives, not my entire face but most of it, last time I don't think it did anything, but this time I took a little less because there wasn't much left in the bottle and now only certain parts of my face are splotchy after taking it, the first time it went away after about 30 min. and now it's still here an hour later. Why is this happening does anyone have any idea? I don't remember this ever happening in the past. Thanks