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Ambiguous rash and syphilis testing.
Hello, doctors. I've developed an unusual and fairly long-lasting rash. My question is in regards to STD testing and what steps, if any, I should take at this point.
My history is as follows:
I am a sexually active young gay male. In the past year, I have had exclusively protected anal sex with two different partners as well as unprotected oral sex with an additional partner. While I always make it a point to assess my partner's HIV/STD status through inquiry, even honest people are often unaware of their STD status.
My last sexual encounter was around nine or ten weeks ago. I performed oral sex on a man and swallowed his semen. Seven weeks after the exposure, I developed a red, dime-sized, oval, and somewhat scaly patch on my arm. A week later (precisely eight weeks post-exposure), I went to a clinic to get tested for HIV and syphilis since I was due anyway. The HIV test and the syphilis RPR both came back negative, so I wasn't worried.
However, about a week later, the patch on my arm still remained active and I broke out into a general rash over my abdomen, back, and a little on my legs. The rash presents as slightly raised red bumps. The rash is only slightly pruritic, and my palms and soles are completely unaffected. At this point I went to a primary care clinic and received a diagnosis of pityriasis rosea, which seems fairly consistent with these symptoms (i.e., an initial patch followed later by a general rash). They gave me some prednisone.
Now, my question. Given my history and these symptoms, is it necessary for me to test for syphilis again at a later date?
My history is as follows:
I am a sexually active young gay male. In the past year, I have had exclusively protected anal sex with two different partners as well as unprotected oral sex with an additional partner. While I always make it a point to assess my partner's HIV/STD status through inquiry, even honest people are often unaware of their STD status.
My last sexual encounter was around nine or ten weeks ago. I performed oral sex on a man and swallowed his semen. Seven weeks after the exposure, I developed a red, dime-sized, oval, and somewhat scaly patch on my arm. A week later (precisely eight weeks post-exposure), I went to a clinic to get tested for HIV and syphilis since I was due anyway. The HIV test and the syphilis RPR both came back negative, so I wasn't worried.
However, about a week later, the patch on my arm still remained active and I broke out into a general rash over my abdomen, back, and a little on my legs. The rash presents as slightly raised red bumps. The rash is only slightly pruritic, and my palms and soles are completely unaffected. At this point I went to a primary care clinic and received a diagnosis of pityriasis rosea, which seems fairly consistent with these symptoms (i.e., an initial patch followed later by a general rash). They gave me some prednisone.
Now, my question. Given my history and these symptoms, is it necessary for me to test for syphilis again at a later date?
MEDICAL PROFESSIONAL
You correctly understand prozone.
I have no personal experience treating pityriasis; we refer suspected cases to dermatologists. I cannot advise about the need for prednisone. But it's "powerful stuff" only in relation to dosage and duration. Certainly I would have no hesitation to take 10-20 mg daily for a few weeks or 40-60 mg daily for 1-2 weeks (which I have done). But if treatment is required more than a couple months, I would do all I could to keep the dose at 10 mg daily or less. You should discuss treatment with the prescribing clinician before taking the drug any differently than on your prescription.
I have no personal experience treating pityriasis; we refer suspected cases to dermatologists. I cannot advise about the need for prednisone. But it's "powerful stuff" only in relation to dosage and duration. Certainly I would have no hesitation to take 10-20 mg daily for a few weeks or 40-60 mg daily for 1-2 weeks (which I have done). But if treatment is required more than a couple months, I would do all I could to keep the dose at 10 mg daily or less. You should discuss treatment with the prescribing clinician before taking the drug any differently than on your prescription.
Actually, I do have an additional question. I apologize; I just didn't think of it earlier. Is the prednisone medically necessary? It's powerful stuff. I'd rather not take it "just because."
Thank you for your advice, Dr. Handsfield. Given the information you've provided, I will simply have another test at a later date for a definitive answer.
After a few moments of research, my understanding of the prozone effect is that it tends to occur when high concentrations of antibodies are present in the lab specimen, which sometimes happens in secondary syphilis or with HIV coinfection.
Since the latter, in my case, we can fairly safely rule out, will a test at the three month point nullify any significant possibility of the prozone effect's occurrence?
This will be my last post to the thread. My thanks go to both you and Dr. Hook for your sex education and prevention efforts. My community in particular owes much (undoubtedly, many lives) to the efforts of you and your colleagues in the past and present.
After a few moments of research, my understanding of the prozone effect is that it tends to occur when high concentrations of antibodies are present in the lab specimen, which sometimes happens in secondary syphilis or with HIV coinfection.
Since the latter, in my case, we can fairly safely rule out, will a test at the three month point nullify any significant possibility of the prozone effect's occurrence?
This will be my last post to the thread. My thanks go to both you and Dr. Hook for your sex education and prevention efforts. My community in particular owes much (undoubtedly, many lives) to the efforts of you and your colleagues in the past and present.
MEDICAL PROFESSIONAL
Welcome to the STD forum.
It is very unlikely your rash is due to syphilis. Your description of the rash could fit with syphilis, even with sparing of the palms and soles. But still extremely unlikely to have secondary syphilis with a negative blood test. And although syphilis can be acquired by oral sex, it isn't especially common; and with the penis being the exposed site, a primary lesion (the chancre) usually would be quite obvious. Finally, although pityriasis rosea is a condition easily confused with secondary syphilis, the diagnosis of that condition probably is reliable if made by a clinician experienced with it. You also are correct that an inital localized lesion (the "herald patch") followed by systemic rash is typical of PR, and not of secondary syphilis.
Having said all that, there is an occasional problem with the syphilis blood tests known as the prozone phenomenon. Without going into detail for the reasons, a sceening RPR test can be falsely negative if the serum is not diluted slightly (with a saline solution) before being tested. Many labs routinely dilute the specimens before testing, preventing prozone. To be safe you might ask about it. But all things considered, I'm really not concerned about syphilis in this situation.
I hope this helps. Best wishes-- HHH, MD
It is very unlikely your rash is due to syphilis. Your description of the rash could fit with syphilis, even with sparing of the palms and soles. But still extremely unlikely to have secondary syphilis with a negative blood test. And although syphilis can be acquired by oral sex, it isn't especially common; and with the penis being the exposed site, a primary lesion (the chancre) usually would be quite obvious. Finally, although pityriasis rosea is a condition easily confused with secondary syphilis, the diagnosis of that condition probably is reliable if made by a clinician experienced with it. You also are correct that an inital localized lesion (the "herald patch") followed by systemic rash is typical of PR, and not of secondary syphilis.
Having said all that, there is an occasional problem with the syphilis blood tests known as the prozone phenomenon. Without going into detail for the reasons, a sceening RPR test can be falsely negative if the serum is not diluted slightly (with a saline solution) before being tested. Many labs routinely dilute the specimens before testing, preventing prozone. To be safe you might ask about it. But all things considered, I'm really not concerned about syphilis in this situation.
I hope this helps. Best wishes-- HHH, MD
You are reading content posted in the STDs Forum
Herpes spreads by oral, vaginal and anal sex.
Herpes sores blister, then burst, scab and heal.
STIs are the most common cause of genital sores.
Millions of people are diagnosed with STDs in the U.S. each year.
STDs can't be transmitted by casual contact, like hugging or touching.
Syphilis is an STD that is transmitted by oral, genital and anal sex.
