Crab pinches that bleed are generally non-toxic, but they are prone to bacterial infections and other conditions that need to be treated accordingly. Crabs are generally non-toxic. If you are caught by a crab and bleed, you should squeeze out some of the blood from the wound, flush it with plenty of water, and disinfect the wound with iodophor. Generally speaking, if the wound is shallow, it can recover gradually by itself, and you should pay attention to keeping it clean and dry. If the wound is narrow and deep, you should go to the hospital to get a tetanus shot. If the wound becomes infected, antibiotic ointment such as mupirocin ointment and erythromycin ointment can be used as prescribed by the doctor. If the wound is serious after being bitten by a crab, you should go to the hospital in time. The use of the above drugs should follow the doctor’s advice, not blindly use their own medicine, so as not to cause adverse consequences.