Ive been dealing with a rash that comes and goes and this has been happening for about a year now. Before the rash comes about, I get a sensation that my entire body is being poked with hot needles; not the pins and needles sensation people feel when they fall sleep on their arm, but a feeling that someone took a bunch of needles out of the oven and started poking me with them. The feeling begins in my arms and feet first and then hits my entire body; from head to toe. The feeling is triggered whenever I step into a hot room, try to exercise, step outside on a sunny day; basically, anything that induces sweat.
This issue goes away whenever I turn the AC on or step outside on a cold day; what happens immediately after trying to cool myself down, is my underarms start to sweat and when it does, the feeling and the rash goes away with in a few minutes. Also, I am only able to sweat under my armpits and very little from my groin area; even wit heavy aerobic exercise, sweat is only able to come out from my underarms and a little from my groin area.
When this first started to happen, I thought it might be a skin issue, so I switch to hypoallergenic detergent, organic moisturizing soap, started using a shower filter, changed my sheets, my vent filters; pretty much the works and limiting my showers to 10 minutes and nothing has helped.
My most recent episode was at a gas station and for the third time, my body got so hot that my muscles started to cramp, as if I just finished playing an hour of basketball in hot weather. This wasnt the first time I started to cramp up; I intentionally let a couple of (prior) reactions last longer than I usually do, in an effort to see how much it would progress. In those "experiments", my body got so hot, I started to cramp and also collapsed running to the kitchen to get a bottle of Gatorade (which was the second time I let it progress, without intervention). Of course it happened again at the gas station (as mentioned above, and while buying Gatorade no less) but this time, I was able to step outside in the cold and immediately started to drink one of the Gatorade.
I finally made an appointment with a PCP (my first time seeing a doctor in several years) and he diagnosed me with a heat rash and prescribed me several different allergy medications. Since taking the medications, the only thing it has done.... was eliminate the rash portion of my reaction; the feeling of being pricked with hot needles is still there. What this led me to believe is that, the feeling of being pocked by hot needles is NOT an allergic reaction. And in fact, the only allergic reaction I was having through out this whole ordeal, was the rash. Well, the rash no longer appears but the feeling still occurs. Also, the feeling occurs when my body attempts to sweat, but cant until my armpits start to finally sweat minutes later, or I intervene by cooling myself down using either an AC, an Ice Pack and/or some frozen bottles in my hand.
Knowing all this, I now know that I need to find the root cause of why my body wont sweat anywhere but my armpits and groin (to a lesser extent). What are the possible causes of anhidrosis and whats tests can I run to find out the root cause of the issue, so that I can treat the cause, not the damn symptoms. Since Im paying for the doctor visits ($125 a visit, not including any tests run) out of pocket, I need to narrow down a possible cause so that I dont end up running several useless tests that have no way of diagnosis the reason for anhidrosis (or hypohydrosis in my case).
Any idea what the cause might be? I realize that no one can diagnose a person online but if I could get a list of what causes lack of sweating, I can at least focus on testing for those possible causes. Simply treating half the damn symptoms, isnt a solution.