Question:

A 29-year old man, non-alcoholic, otherwise in good health presented with 2-week's history of sudden onset of skin eruption. There were yellowish-red papules which first appeared on the arms, subsequently spreading to the buttocks, shoulders and trunk. The lesions were itchy.

Physical examination found 2 to 3mm diameter firm yellowish papules many of which having red halos. They were arranged in crops which were distributed over his buttocks, extensor surfaces of the arms and the back. No lesions were found on the palms, soles or the face. No enlarged liver or spleen was found on abdominal examination.

Investigations showed grossly raised fasting blood triglyceride and fasting blood glucose.

Answer: A. Eruptive xanthomata

The patient has eruptive xanthomata.

Xanthomata are lipid containing papules or nodules that may be found anywhere on the skin and mucous membranes. They are formed by serum lipid infiltrates which are engulfed by macrophages and deposited in the tissues. Depending on clinical presentations xanthomata are classified into plane, eruptive, tendinous and tuberous. They are important visible clues to various metabolic disorders but detailed biochemical investigations are necessary to delineate the underlying disorder.

Eruptive xanthomata present as small, 1-4mm diameter papules, yellowish with a red halo. They are distributed over the buttocks, shoulders and extensor aspects of the limbs. Sometimes they are also found on the lips, eyelids, ears and in the antecubital and popliteal fossae. Pruritus is common. Lesions usually appear in crops and fluctuate with lipid level.

Eruptive xanthomata are associated with hyper-triglyceridaemia. The most common cause is secondary hyperlipoproteinaemia associated with uncontrolled diabetes and alcohol ingestion or drugs such as oestrogens, steroids or retinoids. Eruptive xanthomata may also develop in decreased lipoprotein lipase activity, ApoCII deficiency or increased synthesis of VLDL and primary hyperlipoproteinaemia. In addition to the skin manifestations, other features of hyperlipidaemia e.g. lipaemia retinalis, hepatosplenomegaly and pancreatitis may also develop.

Eruptive xanthomata usually resolve with control of the underlying metabolic disorders.