Xanthelasma — more precisely, xanthelasma palpebrarum — are flat or slightly raised yellow plaques that sit in the thin skin of the eyelid. Under the microscope they are collections of lipid-laden macrophages (foam cells) in the dermis. They are benign, painless, and do not threaten vision, but they are almost always the first thing the patient sees in the mirror, and they grow slowly over months to years rather than disappearing on their own.
Roughly half the patients with xanthelasma have elevated blood lipids — high LDL, low HDL, or a familial dyslipidaemia — and the other half have a completely normal lipid profile. The eyelid skin is thin, low in subcutaneous fat, and prone to showing lipid deposits that would be invisible anywhere else on the face. That is why the lesions favour the eyelids rather than, say, the cheek.
New xanthelasma often appear in pairs on the inner corner of the upper lid, and then similar lesions may show up symmetrically on the lower lid. Patients in Gurgaon and Delhi NCR most commonly come in when the plaque has grown large enough to be noticed in photographs or across the dinner table.