Rashes on the front of the shin are seen commonly with
lichen simplex chronicus which is very itchy and also with this condition, necrobiosis
lipoidica diabeticorum (NLD). It is a condition you see in diabetics or pre
diabetics. It is non scaling, not itchy and just slowly expands. The cause is
not known but it is thought to be related to diabetes induced vascular damage.
Although only about 22% of patients with NLD have diabetes those diabetics who
also have NLD have an increased incidence of neuropathy, retinopathy and joint
immobility. These lesions have recurred around a large plaque that had been
treated with intralesional steroid injections into the inflamed edge. Most
lesions have a raised edge and a central atrophic area where the underlying
veins can be easily seen. Sometimes the underlying fat gives them a yellowish
tinge. A punch biopsy of the edge should always be sutured as injuries here are
very slow to heal. No other treatment has been shown to work in double blind trials.
