What Causes Inflammation On Leg?

Dear Doctor My wife, aged 45 with a weight of 60kg has formed an inflamation in leg in which swollen part part were pinkish and seems to be very soft while touching , this has happend one and half month back. after the medication it has healed and left with blackish mark and after 3 weeks a similar one has formed in the knee with the similar inflamation. now after 3 weeks again has formed the same inflation in the leg. we have consulted a skin specialist and he has express his doubt as it may due to panniculities. which can be confimed only after biopsy. kindly give some input on this decese. whether it is dangerous or incurable?.your kind reply is solicited. She is an alergic person to dust and her vocal cord is get effected if use cold drinks or continues talk Joy