The hard white stuff on the feet is commonly metatarsal warts, belonging to the viral infection of skin disease, in the treatment of dermatology can be considered to do laser or frozen way to remove the warts, after removing the warts, you can apply fusidic acid, clindamycin, erythromycin and other prevention of infection. After the wounds are healed, you can apply acyclovir cream externally, and you need to wear soft-soled and breathable shoes to avoid long-term friction. Plantar warts are viral infections that may recur when the immune system is low. If there are new plantar warts, you can consider freezing or laser treatment again, and you should exercise more to improve your immune system and reduce the chances of recurrence.