It's not beriberi, it's corns on the soles of your feet. The main inducement is friction and oppression, such as during long walking. A certain part of the sole or toe is often pressed by friction, which will gradually form localized keratin hyperplasia. After a long time, an inverted cone-shaped keratin plug will appear in the center and move into the dermis.

Because the tip of keratin plug stimulates nerve endings in dermal papilla, it will cause severe pain when standing and walking. In addition, if patients often wear tight narrow shoes or have deformed feet, they can also cause local friction and pressure on the soles of their feet, resulting in keratin thickening and corns. Clinically, it needs to be differentiated from plantar warts and toes. The plantar wart is infected by human papillomavirus, which leads to nipple-like keratin hyperplasia on its surface. There are black bleeding spots in the middle of dermatoglyphics, and the squeezing pain is obvious. Toe-toe, irregular keratotic patches or strips, smooth surface, unclear edge, generally no pain.