Summary: Necrobiosis lipoidica (NL) is a rare and chronic disease characterised by yellow-brown, atrophic, telangiectatic plaques usually located on the lower extremities, with pathological features of collagen necrobiosis and dermal inflammation. Most cases are seen in those with diabetes mellitus, particularly type 1 diabetes (T1DM), and many without diabetes have evidence of abnormal glucose tolerance or family history of autoimmune disease. In this study, we describe four patients with NL and T1DM. A common theme is late identification and delay in diagnosis. Hence, we discuss the clinical features, need for clinicopathological correlation, and the management and prognostic implications for this distinctive entity. While most remain relatively asymptomatic, others progress to debilitating disease with pruritus, dysesthesia, and pain. Pain is often intense in the presence of ulcerated plaques, a morbid complication of NL. Diagnosis requires the integration of both clinical and histopathological findings. NL has proven a challenging condition to treat, and despite the numerous therapeutic modalities available, there is no standard of care. Hence, in this study, we provide an overview of current management strategies available for NL.
Learning points: Necrobiosis lipoidica (NL) is classically seen in patients with type 1 diabetes. Koebner phenomenon, defined as the appearance of new skin lesions on previously unaffected skin secondary to trauma, is a well-recognised feature in NL. Background skin phototype contributes to variable yellow appearance of lesions in NL. Diagnosis of NL requires careful clinicopathological correlation. NL is a chronic disease often refractory to treatment leading to significant morbidity for the patient and a management conundrum for the multidisciplinary healthcare team. No standard therapeutic regimen has been established for the management of NL.