Lesions on the anterior shin can be a skin cancer or
psoriasis but if red non scaly with a raised edge then the likeliest diagnosis
is necrobiosis lipoidica. This condition is most often seen in diabetics or pre
diabetics where it starts as a small flat pink macule that gradually increases
in size and develops a papular edge. The central epidermis may thin, allowing
the underlying yellow of the fat to appear centrally with prominent veins. If
this area is traumatised it ulcerates easily and is very slow to heal. For
early lesions the best way to stop progression is to inject Kenacort A10 diluted with 3 mls of local
anaesthetic to 2.5 mgs per ml into the
lesion edge. This can be repeated after 4 weeks. Other measures are used to
increase peripheral blood flow such as Pentoxifylline or low dose aspirin and
dipyridamole. Around 75% of patients who have necrobiosis lipoidica will
ultimately develop diabetes mellitus.
