Add me to the chin itch group - maybe there's a budding researcher out there that wants to write their PhD. on us :)
Front of chin only - generally around poorly cared for cats but also other allergens. I've found by acknowledging it, breathing deep and telling myself the environment is clean and safe by body calms down most of the time. Other times a shot of the good ol' inhaler (abuterol sulfate) cleans up my breathing immediately.
I find it odd that taking the inhaler causes my chin to stop itching immediately.