Xanthomas are lipid-rich lesions that signal underlying dyslipidemias. From 2011 to 2022, the Philippine Dermatological Society reported 276 cases, with only 22 occurring in pediatric patients. Familial hypercholesterolemia (FH) is an autosomal dominant disorder with two variants. This case features interdigital xanthomas between the thumb and index finger, which are pathognomonic for the homozygous form and are associated with a higher risk of cardiovascular disease than the heterozygous form.

A 9-year-old girl presented with a two-year history of multiple, asymptomatic, yellowish papules and plaques on her elbows and knees, with no prior trauma or treatment. Interim, new plaques developed in flexural areas, prompting her consultation. Examination revealed yellowish lesions in the webspaces of both hands, knees, elbows, antecubital fossa, and popliteal fossa. Family screening indicated a history of hypercholesterolemia. The lipid profile confirmed hypercholesterolemia, low HDL, and a fourfold elevation of LDL, indicating three times the average risk for cardiovascular disease. Biopsy was consistent with xanthoma. The patient was started on Simvastatin 20 mg daily, along with dietary modifications and exercise recommendations. Family members were also screened. Follow-up tests showed decreased cholesterol and LDL levels, along with reduction in lesion size.

This case underscores the need to recognize xanthomas as indicators of FH. Although many individuals are affected, awareness of the condition is alarmingly low. Xanthomas should not be regarded as mere cosmetic lesions but as warning signs of other underlying conditions that necessitate prompt intervention. Implementing universal screening for children, along with cascade screening for family members is vital.