That’s a blind pimple or cyst — inflammation trapped in the deep dermis with no follicle opening to surface through, so fluid cannot drain on its own. Hormonal androgens, cortisol, and clogged sebaceous glands are the usual drivers; the jawline and chin are the common locations in adults. A flat hydrocolloid patch like Hero Mighty Patch or COSRX does nothing here because there’s no fluid to absorb yet. Use a microneedle patch instead — Rael Microcrystal, ZitSticka Killa Kit, or Hero Mighty Patch Micropoint Large — to push salicylic acid below the surface. A dermatologist cortisone injection flattens it in 24 to 48 hours. Warm compresses 3 to 4 times a day help bring it to a head.