My husband on occasion will get cellulitus (usually from the knee area down to his foot). The infection starts as a blister and will spread. At one ti?

Treat athlete's foot. Recurrent cellulitis (actually lymphangitis) of the lower leg is usually caused by chronic athlete's foot. Bacteria gets in through the fissures between the toes, and is carried into the leg by lymph channels. So while the infection must be treated with an antibiotic, the athlete's foot needs to be treated too, to prevent future infections.
Circulation. Sounds like this could be a serious condition. Does your husband have generalized swelling in his legs before the cellulitis begins? Recommend evaluation by a physician.