What Causes Swelling Along With Pain In Shin And Ankle?

My boyfriend (60 year old male) has a very swollen shin and ankle (left side)- hurts to put any pressure on it and is painful (tightness and sore). I am not sure what to suggest...he refuses to go to urgent care - has the leg elevated and is resting. I don t know whether to suggest something like Aleve or a water pill...can either or both of those hurt? He has had to take antibiotics and steroids in the past for leg issues but no doctor has ever really been able to figure out what it is....(sores on his upper thighs and upper arms....lots of itching but not contagious). I will insist he see a doctor on Monday but what can we do to help before then? I am wondering if it is gout, cellulitus, or a blood clot (however no bumps or veins visable so hopefully not. Thanks for your input