Accuracy of blood tests

[mp7474]

Hello. This is a follow up to the question I posted on 10/25 about a rash on my penis.  45 days after the unprotected oral sex I had a Type II Select test for herpes that came back negative.  When the rash appeared I freaked out and was tested again.(73 days after exposure0.  This time I was given an IgM nonspesific type test and it came back with a prelimemnary level of 1.1 wich is the minimum count for a positive result.  I had chicken pox as a child and did not know if that could cause it.  Is it likely or possible that I contracted HSV1 on my penis and that is what caused the rash, or that the Type II Select test was incorrect?  I am extremely worried now.  What do you reccomend I do?  The rash is gone so there is not way to culture it.  My FP saw it and said it did not look like an STD, but I have no idea how much experience he has with them.  He seemed stumped by it.  Any suggestions or help would be very appreciated!  Once again, the rash appeared the day after sex. It was a red line in a fold of skin that was parallel with my foreskin scar.  It went away after a few days and use of tinactin.  It appeared the next time we had sex in a few more folds.  Did not itch, very mild irritation, nor was it raised or bumpy. When erect, it looked like a few red lines had been drawn on my penis.  I am at my wits end and fear that my marriage is over!  There is a more detailed account of events in the dermatology forum that might help you.  Space was limited here.  What should my next step be!?!?!  Thanks for any help or reccomendations.

[H. Hunter Handsfield, M.D.]

You don't have an infection with herpes simplex virus type 2; a negative HerpeSelect HSV-2 test is reliable.  The weakly positive result on the second test is consistent with your having an HSV-1 infection, but not definitive.

If you really feel you need to know, you can ask your health care provider to do the HerpeSelect HSV-1 blood test, but I don't recommend it because a positive result won't mean anything.  If it is negative, you will know for sure you have never been infected with either HSV-1 or HSV-2; but it probably will be positive, because more than half the population is positive for HSV-1.  In other words, even if positive it will not mean you acquired HSV-1 from your recent sexual exposure.  

Varicella (herpes) zoster infection (chickenpox) doesn't affect either of the blood tests you have had.

You need to stop obsessing about this.  You don't have genital herpes.

Good luck--   HHH, MD

[mp7474]

Sorry to keep troubling you with this, but just for a quick clarification, when you say "I don't have genital herpes"  do you mean just HSV2?  Some of the things i have read classify genital herpes as HSV2 and others classify it as either an HSV2 or HSV1 infection below the waist.  I am just a little confused.  My main concern here is the possibilty of a HSV1 infection on my genitals. Once again, sorry to bother you with this, but all the stuff i have read has obviously scared and confused me a little.  Thanks for your help.

[H. Hunter Handsfield, M.D.]

I don't know whether you have genital HSV-1 infection.  If you have a HerpeSelect HSV-1 blood test and it is negative, then you don't have it.  If positive, you may or may not.  The only way to know for sure you have genital HSV-1 would be if you have a genital outbreak and get a test for HSV from the lesion--not a blood test, but a culture or other test for the virus itself--that is positive for HSV-1.

Based on your symptoms and exposure history, I am pretty sure you don't have genital herpes due to HSV-1, at least not acquired from the exposure you describe.  That's why I don't recommend the HerpeSelect HSV-1 blood test; even if positive, it wouldn't necessarily indicate genital infection--most likely would be due to distant (asymptomatic) oral infection, which most people have.

Finally, it probably doesn't matter, because HSV-1 doesn't usually cause recurrent genital herpes.  Most people have only 1 or 2 repeat outbreaks, then nothing; 40% have no recurrences at all.  Also, asymptomatic shedding is rare, so that genital HSV-1 is rarely transmitted to future sex partners.  There are exceptions, but they are rare.

HHH, MD

[Marshina]

Had an outbreak on my buttocks and got 2 opinions each of which said shingles.Treatment was not effective so I went to another doctor who did blood test and results came back as positive herpes.They did not specify type but did rule out shingles.I have never had a lesion in the genital area but am curious and concerned of the type.Acyclovir and L-Lysine together seem to be effective but I am afraid to stop taking the both or either.