INTRODUCTION: Necrobiosis lipoidica (NL) is a rare chronic granulomatous 
dermatitis that usually appears in the lower extremities. It affects about 
0.3-1.2% of diabetic patients, the majority of whom have type 1 diabetes. The 
etiology and pathogenesis of this disorder are still unclear. NL is 
characterized by skin rash that usually affects the shins. The average onset is 
30 years, with females being affected more commonly. There are very few reported 
cases of necrobiosis lipoidica in children.
CASE REPORT: We report a case of a 16 year old girl affected by type 1 diabetes 
mellitus (15 years disease duration) who developed an erythematous nodular rash 
on the lower extremities and interscapular area. In the suspect of necrobiosis 
lipoidica, a skin biopsy was performed (lower extremities and interscapular 
area). The microscopic evaluation of the pretibial lesions was suggestive of 
necrobiosis lipoidica. The smaller lesions in the interscapular area showed 
signs of perivascular dermatitis which could be consistent with early stages of 
necrobiosis lipoidica. Local treatment with tacrolimus determined a progressive 
improvement of the lesions.
CONCLUSION: In patients with T1DM, diagnosis of NL of the lower legs is usually 
unequivocal. However, diagnosis may be more challenging in the presence of 
lesions with recent onset and/or atypical clinical presentation and unusual 
site. In these cases, NL must always be taken in consideration in order to avoid 
misdiagnosis, wrong/late treatment decisions and progression to ulceration.