PA05 From papules to plasma: eruptive xanthomas revealing hypertriglyceridemia and diabetes in a teenager

Abstract

Eruptive xanthomas are uncommon cutaneous markers of severe hypertriglyceridemia, arising from dermal deposition of triglyceride-­rich lipoproteins phagocytosed by macrophages to form foamy histiocytes (Sorrell J, Salvaggio H, Garg A et al. Eruptive xanthomas masquerading as molluscum contagiosum. Paediatrics 2014; 134: e257–60). Although well described in adults, they are rare in children, where they mandate urgent ­metabolic evaluation due to their association with markedly elevated triglyceride levels and significant risk of acute pancreatitis (Khadka A, Bhattarai S. Eruptive xanthomas as cutaneous manifestation of familial combined dyslipidaemia in an eleven-year-old: a case report. J Nepal Med Assoc 2020; 58: 170–3). A 14-year-old boy was referred with suspected extensive molluscum contagiosum. He reported a 2-week history of multiple papules affecting the arms, legs and trunk. Family history was notable for type 1 diabetes mellitus in his father. Examination revealed hundreds of red-brown and yellowish papules consistent with eruptive xanthomas. Marked acanthosis nigricans was present on the neck, axillae and chest suggesting insulin resistance. His body mass index was normal at 24.9 kg m−2. Blood tests confirmed severe hypertriglyceridemia (triglycerides 44.6 mmol L−1) and undiagnosed diabetes (glycated haemoglobin of 96 mmol mol−1). Elevated C-peptide and negative anti-glutamic acid decarboxylase antibodies supported a diagnosis of type 2 diabetes mellitus. Skin biopsy showed foamy histiocytes within the upper dermis, positive for CD68 and negative for S100 and CD1a, confirming eruptive xanthoma. He received urgent treatment for hypertriglyceridemia and diabetes (metformin, degludec insulin, bezafibrate and semaglutide injection). The xanthomas fully resolved following treatment, highlighting the reversible nature of eruptive xanthomas when underlying abnormalities are effectively treated. This case highlights the importance of recognizing eruptive xanthomas as a cutaneous marker of severe metabolic disease. Early dermatological diagnosis enabled timely intervention, which is important to prevent serious complications such as acute pancreatitis.