you should get medical attention for your brother as soon as possible. these symptoms could relate to a variety of ailments and only a health care professional doing a physical examination can give you a diagnosis. any time a person's symptoms get worse or change suddenly it's worth a trip to the doctor's office. in your brother's case this is especially true because his symptoms are causing him to be unable to walk. i don't want to alarm you but i urge you to seek medical attention for your brother as soon as possible. best wishes to you both!
my 55 yr. old brother has both legs below the knee to toes unusually red swollen warm painfull useless after 20 steps.