Q. Would Zantac make allergy skin test false positive?

Hi doctor,

I have had a history of coughing for a few weeks here and there in spring and fall. It will be fine after about three weeks. Then, my throat will start to itch, and I will begin to have trouble talking. Later, I start coughing explosively. Once I get to the coughing phase, my eyes start watering. It looks like I am crying and I will either cough until I throw up mucus or fluid or vomit if I have just eaten, and then I can breathe again. It happens on the bus, at work, and sometimes at night. When I do not have these odd coughing spells, I feel fine. There are no sore throat, vomiting or GI symptoms. Sometimes I will have the sniffles. I hugged a friend at the dance, and I went from fine to immediate coughing in about 5 to 10 seconds. I will have a few weeks of this, and then it will clear up on its own. Last week, this happened about 10 times, and itchy throat spells where I worked on breathing through it. I am always sucking on throat lozenges during these weeks.

My total IgE level taken during one of these symptoms filled weeks was 736 ug/L, where reference range is less than 416 ug/L for adults. Medications I was on during testing include Zantac (Ranitidine) just in case it is acid reflux and Ibuprofen for menstrual cramps. They did a skin test this week to try and start figuring things out, and two types of dust mite and something else came back positive. Spirometry is waiting on results. I have never been able to run a mile outside without stopping to catch my breath a few times. I got bronchitis a lot as a kid. It seemed like if I got a cold, it would inevitably move to my lungs before getting better. My GP was hesitant to order the total IgE level because she said it was often falsely positive. Would Zantac make IgE or allergy skin tests falsely positive? Is this likely to be allergic asthma? How best should I treat it?