Eruptive xanthomas

A 34-year-old male presented with multiple asymptomatic papules over both the hands, feet, forehead and ears for 10 years. He was a known case of type 2 diabetes mellitus for 9 years and was initially prescribed 500mg of metformin. However, he had been non-compliant with the treatment and had not taken any medications for the past 7 years.

On physical examination, blood pressure was 140/84mm Hg and BMI was 30.07kg/m². Cutaneous examination revealed multiple, yellowish, firm monomorphic non-follicular-based papules on the dorsum and palmar aspect of both hands, dorsum of both feet, ears, forehead, elbows and buttocks (Figure 1). Koebnerization was noted. Tendon examination was normal.

Ophthalmological evaluation revealed 6/6 visual acuity in both eyes, with normal colour vision and pupil reactions. Anterior segment examination was normal. Dilated fundus evaluation showed multiple sclerosed vessels and arteriolar whitening suggestive of lipemia retinalis, with no evidence of diabetic retinopathy. Optic disc was normal. Investigations revealed a serum triglyceride level of >68.1mmol/L, serum total cholesterol of 7.29mmol/L, glycated haemoglobin A1C (HbA1c) of 129mmol/mol, fasting glucose of 21.05mmol/L and postprandial glucose of 21.93mmol/L. Liver and thyroid function tests were found to be within normal limits. Serum creatinine was normal (70.72µmol/L). Differential diagnoses of eruptive xanthomas, generalised eruptive histiocytosis and disseminated granuloma annulare were considered. Based on the classical clinical findings and laboratory investigations, a final diagnosis of eruptive xanthomas was made.

In view of hypertriglyceridemia and uncontrolled diabetes mellitus, he was initiated on oral fenofibrate 160mg, a Peroxisome proliferator-activated receptor alpha and gamma (PPAR-α/γ) agonist (Saroglitazar), dual-acting insulin injection and oral hypoglycaemics. Notable decrease in the number of pre-existing lesions and significant reduction in serum triglycerides (9.1mmol/L) and HbA1c (72mmol/mol) were noted a month after treatment.

Discussion

Eruptive xanthomas are localised lipid deposits in the dermis.¹ They present as asymptomatic, multiple, yellowish dome-shaped papules on Achilles and patellar tendons, extensor tendons of the hands and elbows, eyelids, trunk and buttocks. Early lesions may be pruritic and may demonstrate koebnerization. Other clinical presentations of xanthomas include tuberous, tubero-eruptive, tendinous, planar, verruciform and papular forms. Hypertriglyceridemia and diabetes mellitus are major risk factors, with 8.5% of individuals exhibiting triglyceride levels exceeding 20.1mmol/L being prone to developing eruptive xanthomas.² The most common inciting medications to cause eruptive xanthomas include systemic estrogens, systemic corticosteroids, systemic retinoids and olanzapine.³ Our patient was not on any of these medications.

Differentials to be considered for eruptive xanthomas are generalised granuloma annulare (GA), generalised eruptive histiocytosis and xanthoma disseminatum.

Generalised granuloma annulare manifests with widespread skin-coloured to erythematous papules or plaques on the trunk and extremities, with sparing of head, neck, palms and soles.

Xanthoma disseminatum, a form of non-Langerhans cell histiocytosis, is characterised by red-brown papules and plaques in flexures on the trunk or proximal extremities.

Generalised eruptive histiocytosis presents as multiple asymptomatic, skin-coloured to erythematous papules and nodules over the face, trunk and extremities, characterised by histopathological features of nodular aggregates of large histiocytes and absence of giant cells.

Investigations include evaluation for causes of secondary hyperlipidaemia, such as diabetes, thyroid disease, liver disease or renal disease. Although a confirmatory skin biopsy, which is usually performed for a definitive diagnosis, was not obtained in our patient, the classical clinical presentation of our patient in the context of severe hypertriglyceridemia, uncontrolled diabetes mellitus and a positive response to treatment strongly supports the diagnosis of eruptive xanthomas.

Treatment involves controlling the underlying hyperlipidaemia, which results in improvement of the cutaneous lesions, as was seen in our patient. Alternative therapeutic modalities such as laser or cryosurgery can be considered in situations where medical therapy does not suffice.⁴

Eruptive xanthomas indicates the presence of an underlying metabolic disorder like hypertriglyceridemia and diabetes mellitus, and can often be the first warning sign of cardiovascular risk in such patients.⁴ Recognition and early treatment remains crucial, as it can prevent progression to pancreatitis or atherosclerotic disease.

View Figure 1–2.