Burns caused by caustic soda on the skin usually take 5-10 days to recover gradually. Caustic soda, sodium hydroxide, is a strong corrosive and alkaline chemical, which will lead to burn-like changes in the skin after touching the skin, with local skin burning, pain, and in severe cases, even breakage, erosion, exudation and many other clinical symptoms. For people with milder symptoms, the skin will gradually recover after about 5 days, and the symptoms will disappear quickly. For people with more serious symptoms, it takes about 10 days or even longer to recover after regular treatment. When the skin surface is exposed to caustic soda, it is recommended to rinse immediately with running water to avoid prolonged contact with skin and mucous membranes, and those with serious symptoms need to seek medical attention after rinsing.