My chances of having caught HIV,

I had sex with a prostitute in Hainan, China.

I had protected vaginal and oral intercourse with her, 24 hours later, I had a rash on the tip of my penis.

My the end of my penis now kind of looks kind of like a toadstool. I had similar symptoms once, my doctor said it was probably a side effect of taking amoxicillin 200mg for a chest infection I had at the time back in 2006.

I went to a doctor in China, he said it was probably an allergy to latex, as most STI's do not show symptoms so quickly, he's referred me for more tests tomorrow.

I know the chances of catching STI's with through protected sex are slim, but my only concern is that I had one or two, very small healed shaving scars at the base of my penis that may have come into contact with her.

What the chances that I now have something really nasty, like HIV?

[H. Hunter Handsfield, M.D.]

Welcome to the HIV forum.

First, HIV remains quite rare in China, including commercial sex workers in that country.  However, if you are still in China, you could check with public health officials to learn whether Hainan might be an exception.  Second, you used a condom -- which means no significant risk of HIV transmission even is your partner was infected. Third, even if no condom were used and if she had HIV, the average risk of HIV transmission is once for every 2,000 exposures.  Therefore, for you to have HIV, all three of these very unlikely possibilities (that she had HIV, that the condom failed, and low transmission risk without condom) all would have had to break the wrong way.  The odds against that are astronomical.  You do not need HIV testing after such an exposure, although you may decide to do it for psychological reassurance.  That's up to you.

As for other STDs, the condom was highly protective.  And your doctor is correct that no STD can cause symptoms within 24 hours; 2-3 days is the minimum.  Whatever the cause of your penile rash/irritation, it is not an STD from that exposure.  Finally, healed scars do not risk HIV or other STDs.

It sounds like your doctor is pretty knowledgeable about STDs and HIV.  I suggest you continue to follow his advice.  But I see no cause for concern.

Good luck--  HHH, MD