What Causes Itchiness And Red Marks On Vagina And Chest After Having Sex?

Hi, I am a 57 year old male. I am married but over the years I have had several sexual encounters with men (mostly safe sex). From time to time I get severe itchiness (but no visible mark on my scrotum except sometimes it is reddish). At the moment I have such itchiness and have been putting cannisten cream on it but the itchiness still seem to be there but the skin is not red. It does seem worse when I am sweaty. I don t know whether it is just fungus or parasites. I had a severe parasite attack some years ago where I had to shave all my body hair and sometimes I wonder whether it is still something to do with that attack. Can parasites be transmitted sexually. I am also getting some itchiness over other parts of my body although not severe. Is there something I can do or get off the shelve with having to consult a Doctor as I find it quite embarrassing. One other thing, I sometimes get some itchiness and slight reddish mark on my chest. Do you think this is connected with the possible parasite infection or could it be due to the recently discovered small cysts on my liver. I also suffer from reflux. Thank you for your advice.