Welcome to the forum. Thanks for your question; I'll try to help.
I can provide a lot of reassurance merely from the title you chose, before I have read the question itself. HIV has never been reported to be transmitted by cunnilingus, either from the vaginal to oral partner or vice versa. In general, cunnilingus is very low risk for all STDs and is clearly zero risk for some, probably including HIV.
Now I have read the question. It does not change my initial, off-the-cuff assessment. You were not at any measurable risk of HIV, both because of the nature of the exposure and the low chance your partner was infected. Your symptoms are not especially suggestive of a new HIV infection, and in any case they started much too soon; HIV can't cause any symptoms sooner than about 7 days after exposure, and usually it's 10-20 days.
In fact, the symptoms were too soon for any infection at all from the sexual exposure. They suggest you may have caught a cold (e.g. by kissing her) --- but even cold symptoms don't start the next day; usually it's 3-5 days. So you caught a cold somewhere else, a few days before the sexual exposure.
I also doubt your lip blister is herpes. The timing is OK for a new HSV infection, but initial oral herpes usually causes multiple blisters and lots of painful sores in the mouth and severe sore throat. And within 13 days a herpes blister would have evolved to an open sore and scab, and would be well on the way to healing by now. As for the skin on your arms, I believe you have put your finger on the most likely explanation: your anxieties about this sexual exposure are making you notice normal variations in skin tone. I doubt anything is wrong with the skin of your arms. Even if there were, HIV wouldn't do this.
Those comments answer most of your questions. It isn't possible to quantify an exceedingly unlikely event; the simple fact that HIV has never been known to be transmitted by cunnilingus is the best I can do. The biological reasons for the low risk don't matter much one way or the other. And since gum disease like yours is extremely common, you can assume billions of episodes of cunnilingus by persons with such problems, and still no known HIV infection.
The only slight concern I have is your oral "blister". For the reasons already stated, I very much doubt it's herpes. But you might want to have it professionally evaluated to be certain.
For all these reasons, you do not need HIV testing from a medical or risk assessment standpoint, and I see no reason you should not resume unprotected sex with your regular partner -- except perhaps avoid kissing an performing cunnilingus on her until and unless your oral lesion has cleared up and/or has been evaluated professionally. From the HIV standpoint, if I were in your circumstance, I would not be tested and would have continuned unprotected sex with my wife without fear of infecting her.
I hope this has helped. Best wishes-- HHH, MD
Dear Dr. HHH
Thank you for the prompt reply and reassurance.
I did not have any tingling on my lip before the lesion appeared 3 days post the cunnilingus episode. It has not crusted or become an open sore. It is approx. 0.2 millimetres in size, raised, looks water filled, and non tender. It is in the centre part of my inner upper lip mucosa. I will see my doctor about it this week. If it is herpes does that pose any risk for me in light of my cunnilingus episode with the sex worker and HIV transmission? I have read reports saying that co-existing STIs can increase HIV transmission but I am not sure what that means exactly. Do I have to have a pre-existing STI to be at risk or does it mean the person I gave cunnilingus too has to have a pre-existing STI? In any case whatever the situation can i take from your earlier advice that you still would not recommend HIV testing for my exposure?
Thank you again.
From this description, your lip lesion almost certainly is not herpes and this does not change my judgement about your risk of HIV from the exposure described, which remains zero. This doesn't change my advice about testing. Of course, you are always free to be tested anyway, if my reassurance doesn't settle your anxieties about it and you would be further reassured by a negative test result. Discuss this, as well as the lip lesion, with your doctor at your upcoming appointment.
Dear dr. Hhh
Thank you fir your recent comments and reassurance regarding my exposure.
Just to update you , I went to a oral medicine doctor regarding my lip lesion and he felt it was a Mucocele most likey due to trauma to the upper inner lip from biting .
I would be grateful for your advice on one further matter. I am now coming up to almost 3 weeks since the incident. 2 days ago I noticed some subtle red areas on my chest. They were very small circles, would blanch on pressure and not itchy. They came one at a time and dissapeared overnight . They were isolated and only a handful. They were not raised. Is this similar to a seroconversion rash or again do you think it is merely anxiety playing with my mind .
Thank you again for your expert advice .
The spots on your chest have nothing to do with any of this. This doesn't sound abnormal, just natural variations in skin tone. You're probably examining yourself too closely out of anxiety.
With my comments and your doctor's reassurance, you should not be at all worried any more. That will end this thread.