HSV-1 DFA positive, seronegative

[lasante]

Hello, Doctor,

I am a 44-year-old female.  Last year, while under a great deal of physical and emotional stress, I had right-sided back and shoulder pain, which I initially attributed to a pulled muscle.  I then developed some lesions over the area.  The dermatologist swabbed a few of the lesions and sent for DFA, although he felt it was most likely shingles (I had had chicken pox some years earlier, as an adult).  The DFA results showed positive for HSV-1.   I have never had a cold sore nor genital lesions, but I realize that many people with herpes simplex infections are asymptomatic.  Still, I was surprised, since the process had walked and quacked like shingles.  

A month ago I discovered that my partner had been having two long-term affairs with other women.  I went for testing and the (blood test) results showed that I am HIV-1 and HIV-2 AB negative, hepatitis C negative, and the RPR was nonreactive.  HSV AB IgM was not detected, HSV-1 IgG was nonreactive (0.03, index <0.90), and HSV-2 was nonreactive (0.08, index <0.90).  

My question is: Why would the swabbed lesion sent for DFA show positive for HSV-1 and my blood work show no HSV antibodies?  I thought DFA was very accurate.  Is it possible for VZV to be mistaken for HSV?  Do I need to have further testing?  If so, what kind?

Thanks for your help.

[H. Hunter Handsfield, M.D.]

This is a peculiar situation and I'm not sure what's going on, but on balance, I believe it most likely that the DFA test was in error and that in fact you had herpes zoster (shingles).  It is very rare to have HSV-1 skin lesions away from the face or genital area.  There is a condition called herpes gladiatorum, in which HSV-1 pops up on the bodies of wrestlers, because of their exposure to opponents' oral herpes.  But unless the infected area was directly exposed to an infected person's mouth, I have to doubt the HSV-1 diagnosis.  Further, I have never heard of an HSV infection starting out with the sort of pain you describe, followed later by skin lesions -- but that sequence is normal with shingles.

The direct fluorescent antibody (DFA) test is inherently less reliable than culture for HSV.  I don't know the actual likelihood for lab error, but combining the clinical picture plus your negative blood test for HSV-1, I have to assume you in fact had singles and that the lab report of HSV-1 was in error.  To be even more certain, you could have a repeat HSV-1 blood test 3-4 months from now.  Most like it will remain negative.

Whatever else, this isn't an STD issue.  Even if it turns out you have a very atypical HSV-1 infection and not shingles, I see no connection with your partner's sexual exposure to other partners.

I hope this helps. Best wishes--  HHH, MD

[lasante]

This does indeed help.  Many thanks for your very quick and informative response.  

Cest Moi