What's the cause? Cellulitis is basically a visible inflammation (itis) of the skin and soft tissues (red, hot, swollen and tender) . It can be caused by many things including sunburn (radiation), trauma (sprained ankle) or poor vein circulation (stasis dermatitis). It need not be caused by bacteria. If you have repeated episodes of this, get to a wound care or vascular specialist, the diagnoses you have is wrong.
Cellulitis timing. Cellulitis may take weeks to resolve; it all depends on the tissue concentration of the pathogens. Many times it can be localized to a small area; other times it can be widespread. Proper cleansing of the skin and oral antibiotics are necessary to run its course.