If you were already sunburned and your skin was exposed for about an hour without sunblock protection and now your burn has a small red patch but isn't itchy with blisters could it be cancerous?

skin cancer generally takes many years to develop. Cancer does not suddenly appear in the middle of a burn; it does, however, develop because of sun exposure in the past. It sounds like you may have developed a worsening of the burn you already had. The serious type of skin cancer typically looks more like an irregularly shaped mole that is dark, not a "red patch." If you are concerned, though, you can certainly have your skin checked out. Hope this helps! Dr. B.