A diagnosis erupting from within

ABSTRACT

We report a case of eruptive xanthomas in a 31 year old Caucasian man with a background history of poorly controlled Type 2 diabetes mellitus, obstructive sleep apnoea and fatty liver disease. He developed a widespread pruritic rash which started on his left arm 9 h after his first dose of the Pfizer covid vaccination which progressed to involve bilateral upper limbs, lower limbs and abdomen. However, he presented a week later with acute abdominal pain and was later admitted to ICU with pancreatitis resulting in diabetic ketoacidosis. Dermatology were consulted for management of his pruritic eruption and possible covid vaccination adverse reaction. Physical examination revealed multiple excoriated yellow to pink papules. His bloods showed a total cholesterol of 31 and triglycerides of 157. A biopsy was taken which demonstrated perivascular and periadnexal foam cells in the superficial to mid dermis consistent with eruptive xanthoma. He was commenced on fenofibrate to manage his hypertriglyceridemia and insulin to manage his diabetes. This case highlights the rarity of eruptive xanthomas and that it can go unrecognised or misdiagnosed if not considered. Clinicians should consider a biopsy to confirm the diagnosis and consider differentials of Non-Langerhans cell and Langerhans cell histiocytosis, disseminated granuloma annulare and sarcoidosis. Eruptive xanthomas are lipid deposits in the skin in the context of high triglycerides >20 mmol/L. They are characterised by firm 2-5 mm papules that commonly involve the extensor surfaces. The papules can be pruritic or tender. The xanthomas usually resolve within two weeks of normalisation of triglyceride levels, as observed in this patient. Effective treatment options include dietary modification and lipid lowering medication such as fenofibrate. In refractory cases, surgical excisions, cryotherapy and ablative lasers such as Er-YAG and CO2 have been reported . Clinical photos and histology will be presented for discussion.