BACKGROUND: Necrobiosis lipoidica diabeticorum (NLD) is a granulomatous skin 
reaction found in < 1% of diabetic patients. Our purpose was to determine if NLD 
represented areas of cutaneous ischemia.
METHODS: Using laser Doppler flowmetry, we measured cutaneous blood flow in nine 
diabetic patients at NLD lesions and at contiguous uninvolved sites. Flow values 
were also determined at several reference sites noncontiguous with the NLD 
lesions and compared to age- and sex-matched controls: 24 diabetic subjects 
without skin abnormalities, 18 diabetic patients with dermopathy, and 40 
nondiabetic subjects.
RESULTS: NLD lesions exhibited significantly higher blood flow (4.8 +/- 0.7 
ml/min/100 g) than areas of unaffected skin close to the lesions (1.2 +/- 0.1 
ml/min/100 g) (P < 0.01 for both comparisons). There were no significant 
differences in flow between normal skin sites in NLD patients and normal sites 
in diabetic patients without skin lesions.
CONCLUSIONS: Our findings refute the hypothesis that NLD is a manifestation of 
microvascular ischemic disease of the skin. The increased blood flow seen in NLD 
lesions suggests an ongoing inflammatory process.