Intertriginous planar xanthoma secondary to dyslipidaemia in an infant

A 16-month-old male infant presented with multiple asymptomatic yellow dermal plaques in his flexural regions from ten months of age. There was no family history of hyperlipidaemia or premature cardiovascular disease. Investigations revealed elevation of serum cholesterol (9.8 mmol/L), low-density lipoprotein (LDL 8.0 mmol/L) and alkaline phosphatase (665 units/L), but triglycerides, cardiovascular review and echocardiogram were all normal.
Intertriginous planar xanthoma secondary to inherited dyslipidaemia was diagnosed. LDL receptor gene testing for familial hypercholesterolaemia detected one variant of uncertain significance. Apolipoprotein E genotype results for the parents were normal, excluding dysbetalipoproteinaemia. The differential diagnosis in this setting includes sitosterolaemia or lipoprotein X. Further genetic studies are pending.
Accurate diagnosis of underlying metabolic disease is essential due to the poor prognosis and complex management required. Differential diagnosis of paediatric intertriginous planar xanthoma will be discussed.

Dr. Xinyi (Cynthia) Yang