A 32-year-old man presented with a yellow, papular rash on the buttocks and extensor surfaces. His medical history included diabetes mellitus, alcoholism, obesity, and polysubstance abuse. Laboratory results disclosed a serum triglyceride level of 5,793 mg/dL. The diagnosis of eruptive xanthomas was made.
Dr Muhammad Wasif Saif of the NIH, Bethesda, Md, comments that eruptive xanthomas are raised, yellow, superficial, papular lesions that are surrounded by an erythematous base. The rash occurs predominantly on the buttocks, arms, legs, and back; it is rarely seen on the face, soles, and palms. The distribution of the eruptions may be related to pressure or mild trauma at the sites.
Eruptive xanthomas strongly suggest an underlying hyperlipidemia (type I, IV, or V). Chylomicrons and their remnants have been demonstrated intracellularly (macrophages) and extracellularly in these lesions. Uptake by macrophages in eruptive xanthomas probably represents an alternative mechanism for chylomicron catabolism when lipoprotein lipase activity is impaired or saturated.
Reduction of elevated triglyceride levels causes the eruptive xanthomas to regress. Within 6 weeks of triglyceride lowering, the lesions appear much flatter and lose their yellow tinge. They disappear completely in several months. Since adequate medical therapy to treat the underlying condition always resolves the xanthomas, surgical removal and cryotherapy are not required.