How do i avoid getting cellulitis from a hematoma?

Depending on cause: If your hematoma developed after a surgery, we tend to treat it with oral antibiotics as the would has been exposed and you'd have a higher risk of infection. However, if the hematoma developed after a blunt trauma that did not cause open broken skin, then the risk of infection is low, and we simply allow your body to slowly metabolize the clot. You should see your doctor to examine the area.

Real answer: A hematoma is a collection of blood below the skin. As it is absorbed, there may be inflammation which is a normal part of healing (red, hot, swollen, and tender) and not bad. Unless the skin is broken, your risk of getting infected is essentially zero. Your body can do it's own thing. Save the lotions and potions for the unusual types of injuries. Yours is straightforward and will resolve fast.