Dr. Bob,

Firstly may I commend you on the fantastic job you are doing. Your selfless advice has been a source of great solace to me in the last few months since my potential exposure. Now to my question. I have read in one of your previous responses that a thirteen week negative ELISA is definitive except in cases of depressed immune system or taking immuno-depressant drugs. Since I am not a medic, can you tell me if this includes anthistamines? I was taking Piriton for an allergy for two weeks during the window period. I have now tested at 13 weeks and the result was negative. My exposure was broken condom during insertive vaginal sex with sex worker (unknown status)and fingering her vagina with a few-hour old (quite deep but no bleeding) cut on my finger. I won't bore you with the details of my non-specific symptoms at 2.5 and 6 weeks post-exposure. The bottom line is can I woo-hoo or would these drugs have an effect on development of antibodies? Very grateful for your response, and I will be making a substantial donation to your foundation.

Many thanks.

Hi,

"Never asked before?" . . . . Hmmm, you didn't search the archives very carefully, because actually I have answered the antihistamine question several times already! So I'll just reiterate briefly. Antihistamines do not affect HIV test results, the ability of the body to make anti-HIV antibodies, or the duration of the window period.

WOO-HOO! And thank you for your donation! With over 8,200 men, women and children dying of HIV/AIDS each and every day, your support is warmly welcomed.

Stay well.

Dr. Bob