I have a mild latex allergy and I'm adhd (meaning I also have sensory issues). I quit wearing underwear when my mum finally let me pick out my own clothes at about age 9. I'd wear a swimsuit under shorts, but the rest of the time just went commando... and still do. I only wear underwear under dresses or for sex schtuff.
The leg holes in underwear trigger the allergy. My skin doesn't get red... it just starts to break down. It doesn't hurt, exactly, nor itch, nor burn... it's just reeeeally uncomfortable/weird feeling UNTIL I get to the last layer of skin and then it breaks and gets very very infected. If I have to wear underwear frequently I usually end up with a lowgrade fever (not super typical with allergies, but it's how my body responds). My usual temp (latex free) is 97.4. On latex I hang out at right about 99-99.5. My mum never caught it, because she didn't know I ran "cold".
TMI... but the first sign of my skin breaking down from underwear is the *smell*. If I ran my finger along the crease between my legs and vaveejay it would smell like feet or worse. NOT wearing underwear, it smells like skin. That area gets quite sweaty. Sweat + latex allergy + beaking down skin = a vile smell. My mum always claimed it was from not washing well (deep sigh... As an adult who showers 3 times a day, and a child who bathed twice a day I can guarantee you it's not and it wasn't). My allergy has gotten worse as I've aged. A single day in underwear starts breaking down my skin. Sex with a latex condom (oy!)... the burning!!! I got new contacts my doc didn't mention were latex based (nor saw the giant red flag in my chart) and my eyes swelled shut. It's a very MILD allergy... but the allergy makes underwear a pain in the.... well yeah.