[Question #2266] Test Result Confidence

44 months ago
Hello,

How confident should I be in the following test results? I had unprotected vaginal and oral sex over 3 months ago. Since then, I've tested negative for chlamydia/gonorrhea at 16 days post encounter, HIV (4th Gen./Antibody) and Syphilis at 30 days post encounter, and HSV1/HSV2 (IgG) at 87 days post encounter. The reason I'm concerned is because I've had a red scrotum for about two months that has an intermittent mild burning sensation, and raw, irritated skin on my penis head. I've had crazy anxiety over this and would just like to hear some expert opinions. It just seems to convenient that this came about after a really stupid/careless one night stand. Needless to say, I haven't had any sex of any kind since the encounter mentioned.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Welcome. Thanks for your question.

FYI, I scanned your two discussions with Terri about herpes. I agree with her opinions and advice.

There are no STDs that cause red scrotum or "irritated" penile skin, and I'm confident that you don't have any STD and certainly no reason to be concerned about HIV (that is, no infection due to immune deficiency from HIV would be likely to cause such symptoms). Most important, the tests you describe are highly reliable. However, for 100% reliable HIV and syphilis results, you should have additional testing; the 4 week results of the tests you had are 95-99% reliable. That doesn't mean there is a 1-5% chance you have HIV or syphilis. Both of these are very rare in even the most sexuallly active women in the US and most industrialized countries -- and for HIV, even if your partner were infected, the transmission risk from a single exposure like yours averages once for every 2,500 exposures.

If your penile/scrotum problem has anything to do with the sexual exposure -- which I doubt, regardless of the timing -- I would chalk it up to a yeast infection, which occasionally can cause genital rash in the male partners of women with vaginal yeast; or perhaps to initiation of an allergic reaction by exposure to spermicide, a perfume, and so on. Such initial inflammatory reactions can become self-sustaining.

But really this is just guesswork. On the bookshelf at my left elbow as I type this, I have a book titlted Genital Dermatology Atlas. As the name implies, it is filled with photos and descriptions of genital area skin problems. Of the 300 pages, exactly 15 are devoted to STDs. In other words, the large majority of genital rashes or other skin problems are not STDs, and almost as big a majority have absolutely nothing to do with sex. Some are genital-specific conditions, and others are various skin problems that can occur anywhere but happen to involve the penis or scrotum. Jock itch comes to mind, for example, at least for the scrotum.

Have you seen a doctor, preferably a dermatologist? Most likely s/he would be able to make an immediate diagnosis. But in the meantime, I really don't think this is anything serious or that it has anything to do with your sexual exposure 3 months ago. If you'd like to put a final conclusion to HIV and syphilis, have another test for each at this time. But stay mellow in the meantime; I'm sure they will be negative. (If I were in your situation, I wouldn't feel a need to do it. But I suspect you'll be more reassured by the negative test results than anything I can advise based on probability and statitistcs.)

I hope this has been helpful. Let me know if anything isn't clear.

HHH, MD
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44 months ago
HHH,

You're the man! No disrespect to Terri in any way, but I was kind of hoping you would answer. The reassurances from experts like the two of you are what I need. I will indeed do one more HIV/Syphilis test. You've mentioned anxiety-related issues in the past causing symptoms similar to mine; I feel this could very well be the case. Prolonged focusing and dwelling on a huge mistake that I'll never make again. I'm about 1 week in to a ketocanazole treatment....I figure at this point I might as well stick it out for another week before going to see a derm. His appointments are booked through this month anyways. For peace of mind's sake - and I meant to ask Terri this - can you explain to me how HSV1 and HSV2 are NOT spread through sex and kissing? I guess I was under the impression that if you slept with someone who has herpes, then it's a forgone conclusion that you also have herpes. Not so apparently...
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
For herpes, the best data are for HSV2, in the study that showed the prevention effectiveness of valacyclovir. In that research, couples in which only one person had genital HSV2 were enrolled, half treated with the drug and half with placebo. In the placebo group, who had an average frequency of unprotected vaginal sex 2-3 times a week, 5% (one in twenty) of the uninfected partners acquired HSV2. It works out to roughly one transmission for every 1,000 vaginal sex events. That is despite the fact that infected persons have virus present in the genital tract 10-20% of days. In other words, not all exposures result in transmission. HSV1 transmission hasn't been studied in this way, but we know that people who have had oral HSV1 infections have the virus present in their mouths around 25% of days. But if you think about it, those persons kiss friends and partners all the time without those people cacthing the virus. We don't know the actual per exposure risk, but it's probably a lot lower than the 1 in a thousand just quoted for genital HSV2.

The biological reasons for all this are complex and not fully understood. But it's also true for most human infections. Most people exposed to colds, influenza, tuberculosis, syphilis, or measles don't catch it. Some are much more infectious than others -- of the ones just mentioned, measles is on the high side, TB much less frequent.

Does that help?
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44 months ago
Thanks Dr. H,

Last question. Based upon your decades of expertise and the details of my story, what do you think my likelihood of contracting herpes was from this encounter? Assuming that she was indeed infected at the time of sex and was shedding asymptomatically. I live and breathe probability everyday as an engineer, so transmission rate numbers are medical lingo that I can appreciate. 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
44 months ago
Based on the exposure alone, I would have estimated the chance of herpes as no higher than one in 1,000. At this point, with no symptoms typical for herpes plus the negative blood test 9+ weeks after the sexual event, I would say the chance you were infected is 1 in 100,000 or thereabouts. Tops.

That concludes the two follow-up comments and replies included with each question, and so concludes this thread. Also, this being your third question on this topic, I'm going to ask there be no more. The forum does not permit repeated questions on the same topic or exposure. Future new questions about this exposure, testing, and your fears about herpes or other STDs will be deleted without reply and without refund of the posting fee. This policy is based on compassion, not criticism, and is designed to reduce temptations to keep paying for questions with obvious answers. In addition, experience shows that continued answers tend to prolong users' anxieties rather than reducing them. Finally, such questions have little educational value for other users, one of the forum's main purposes. I trust you will understand.

Best wishes and stay safe.

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