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Avatar universal

Syphilis/Herpes fears


After getting worried about a suspicious sexual activity in January.
( I have posted a question here : http://www.medhelp.org/posts/HIV---Prevention/Breast-Milk---cut-on-tongue---HIV/show/2089841#post_9905816)
I got a HIV DUO test at 7 weeks and a complete STD test done at 3 months after the exposure, everything came back negative.

My concern is, I took 'bactrim' for 10 days, I stopped it about 5-7 days prior to taking the Complete STD Test.
While I understand that bactrim/anti-biotics donot have any effect on HIV Test, I am not quite sure about Syphilis test.
My concern is especially for syphilis because recently I developed spots/rashes on my penis head. I went to my doctor and he tested me for
herpes ( culture test & blood test (igg/igm) all came back negative).

These are some pictures of the spots/rash:
Rash is healed now:

May 1: http://i60.tinypic.com/2n87fwz.jpg
May 2: http://i59.tinypic.com/rbeh5s.jpg
(a swab is taken when it looked like this, herpes culture came back negative)
May 10 : http://oi57.tinypic.com/n5fqsy.jpg (Rash seemed to heal)
May 17 : http://oi62.tinypic.com/qzki8y.jpg
( 2 New spots appear at different locations, one to the top left, another at bottom right
a swab is taken when it looked like this, herpes culture/Blood test came back negative).

My fears are not specific to this one exposure as i didnot get tested for STDs in past 3 years.
Also,I didnot have sex after Jan 10,2014. so, nothing new caused the rash/spots.

My questions are:

A. Does Bactrim have any effect on Syphilis Test?

B. Does the rash/spots in the pictures look like Syphilis rash?

C. Can I take comfort in my negative herpes culture & Blood tests?
5 Responses
300980 tn?1194933000
Welcome back to the Forum.  I am sorry that you continue to worry about your exposure.  I'll try to provide further reassurance.  I will not however look at the pictures you have posted. We do not look at pictures on this Forum as they are often misleading and rarely helpful.  

Going straight to your questions:
A. Does Bactrim have any effect on Syphilis Test?
No. sulfa drugs, including Bactrim have no effect on syphilis or syphilis tests.  I would add however that these drugs can commonly cause rashes thensleves.

B. Does the rash/spots in the pictures look like Syphilis rash?
See above, we do not look at pictures on our site.  Sorry.

C. Can I take comfort in my negative herpes culture & Blood tests?
Yes, your results are further string evidence that you do not have these infections.

My sincere advice is no not worry further and to move on without concern.  If your rash continues to worry you I suggest you have your doctor or a dermatologist take a look. There are many non-STI dermatological conditions, including fungal infections that can cause rashes of the sort you describe.  

I hope my comments are helpful.  EWH
Avatar universal
Thanks Doctor,

I am very disappointed in myself for getting these fears but the rash made me think about all possibilities.

Regarding Syphilis:

I have read that some anti-biotics do interfere with syphilis test, but was not sure if Bactrim falls in those categories.
What is the reasoning in saying Bactrim doesnt interfere with the test, when some other anti-biotics might.
Please understand, I am not trying to question you,just trying to understand better.Thanks for clarifying.

Is a 3 month window period good for a syphilis test? I took the test from planned parenthood, I dont remember if it is RPR or something else.

based on me taking 'bactrim' and getting tested at 90 days.Is there any need for me to get retested?
sorry for being repetitive.

Regarding Herpes:

I understand the blood tests are very complicated and it is not possible to tell anything from blood tests with 100% accuracy.
I also understand that false negatives are common with Blood test.
since, I got these test when the rashes/spots are physically present (the swab culture is also negative)
Can I consider them more accurate than someone who had a blood test with no symptoms?
300980 tn?1194933000
I repeat, despite what you have read, Bactrim would not interfer with your tests and your results do not need to be repeated.  

I have told you that I see no reason to worry about herpes. I still feel that way. You will have to decide what to do.  EWH
Avatar universal
Thank you so much Dr.Hook.
Avatar universal
Dr Hook,


Yesterday, I was at a strip club and sucked on a dancer's breast for a few seconds..may be 30 secs at the most, she is not lactating. I don't have any ulcers, cuts/openings on my lips or in my mouth/tongue. It was dark..as much as i could see..I didn't see any cuts/injuries on her nipple, it tasted salty..probably sweat.

Is there any chance of getting any STD this way?...I am 90% certain that she didn't have any cuts...but, if she did, would that change anything?


This is probably out of your domain, but, i think i am turning into a hypochondriac..and am worrying about every minor(safe?) sexual encounter.

I am also worrying about minor things,thinking its a symptom for something. last week, I got a blister on my thumb and I freaked out, thinking it could be herpes.

How would I go about controlling this? would you suggest consulting a mental health professional?

If this comes under a new question, please let me know and i will post it as new question.

Your answer is much appreciated.

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