Ulcer status at presentation, after standard therapy and following treatment with bosentan. (A and B) Wagner grade III heel ulcer on admission showing exposure of the calcaneus with an inflammatory aspect and very limited granulation tissue covered by purulent, fetid exudates. (C and D) After three weeks of standard therapy, little improvement was observed, and after five months of conventional local and systemic therapy, the ulcer remained at Wagner grade III, affecting the total posterior face with partial exposure of the calcaneus but sparing the Achilles tendon. (E) Notable improvements were observed in the heel ulcer after the initiation of bosentan therapy and two weeks' treatment at a maintenance dose, with marked granulation tissue apparent on the heel. (F) Complete healing of the ulcer was observed after a total of 21 weeks of bosentan therapy.