Syphilis rash or other STD?

[Paddo63]

First my medical background. I was diagnosed with multiple myeloma ( blood cancer) 5 years ago. I underwent high dose chemo and a stem cell transplant 4.5 months ago. I am currently on chemo one day a week. I have been on the same drug most of the year without any bad side affects. Besides the myeloma I am fit and healthy although the treatment does make me tired at times. My blood is tested weekly and nothing out of the ordinary has been noted.
Just over 7 weeks ago I had unprotected oral sex (both giving and receiving) with another man. We also masturbated our penises together for a few minutes. The room was well lit and I didn’t notice and sores on the mans penis or body. A couple of weeks after this encounter I noticed a reddish brown mark 3/4 inch round on the outside of one my thighs.  I noticed a similar mark on my waistline near the centre of my back. The skin on these marks is dry and shiny. They don’t itch. Over the last 2 weeks about 25 smaller red marks have appeared on my upper legs between my waist and knees mainly on the inside of the legs in the shorts area and vary in size. The older marks gradually get darker and fade over time but are still visible. I can only see a couple of red marks on my stomach which are recent.
In addition, about 3 weeks ago I had a red raised bump around a hair follicle near the base of my penis which looked similar to an ingrown hair. I never saw any open skin or a sore there although the skin peeled slightly. And I haven’t had a chancre like you see in the std photos or any other symptoms.
So does this sound like Syphilis or HIV?
I have back-up supply of Amoxicillin which my specialist gave me in case I pick up an infection. Would the Amoxicillin if it is Syphilis? Thanks for your help.

[biology2017]

Hi

1) my opinion is that you shouldnt be hunting for the causes for your rash. It is the job of your doctor to do so

2) if stds are your conern, speak to your doctor and get tested

3) possible conditions: plaque, erosion, lichenification, hyperpigmentation... The list goes on

[biology2017]

Folliculitis

[Paddo63]

Thanks for your input.  I agree the red raised bump around a hair follicle near my penis is probably ingrown hair although it has been documented that a syphilis sore could be mistaken for the same. However, the rash is not indicative of folliculitis as it appears where no hair follicles are inflamed and in most cases present.

[Paddo63]

since posting my question my rash is increasing. could a Doctor offer their opinion please. as a precaution i have started a course of Amoxicillin.

[Life360_Dave]

Hi, only testing would confirm infections but syphilis is contract at point of contact so any chancres would appear on your penis or mouth area also they are not sypmptoms as your describing anyway. You cant get HIV from oral sex so you can rule that out also.

[Paddo63]

Hi, thanks for your reply. So in your opinion, does the rash sound like any other STD?