The most common laboratory abnormality in patients taking a systemic retinoid, such as isotretinoin or bexarotene, is hypertriglyceridemia.
Retinoids are agents that are structurally related or similar to Vitamin A (also called retinol). Like Vitamin A, they inhibit inflammation, keratinization, and cell growth in the skin. They are used in a variety of dermatologic conditions including acne vulgaris, psoriasis, cutaneous malignancy, HIV-associated eosinophilic folliculitis, and disorders of keratinization like Darier’s disease or lamellar ichthyosis.
Systemic retinoids include isotretinoin, acitretin, and bexarotene. Isotretinoin is a first-generation retinoid that is a safe and effective treatment for severe, nodulocystic, and/or recalcitrant acne vulgaris. Acitretin is a second-generation retinoid that is used to treat severe psoriasis. It is considered a first line treatment for palmoplantar psoriasis that is recalcitrant to topicals. Lastly, bexarotene is a third-generation retinoid that is used in the management of mycosis fungoides (MF) and other forms of cutaneous T-cell lymphoma. The most common laboratory abnormality in patients using systemic retinoids is hypertriglyceridemia.
Isotretinoin and acitretin cause hypertriglyceridemia in ~50% of patients and hypercholesterolemia (generally total cholesterol and LDL) in ~30% (Koo et al., Adv Dermatol 1997). Furthermore, bexarotene causes hypertriglyceridemia in ~80% of patients and hypercholesterolemia in ~50% (Duvic et al., J Clin Oncol 2001). Patients with significant increases in triglycerides can develop acute hemorrhagic pancreatitis or eruptive xanthomas. Lastly, the incidence of acute hemorrhagic pancreatitis is higher for bexarotene than the other systemic retinoids.
Clinical Pearl: Patients treated with systemic retinoids can develop hyperlipidiemia. The most common lipid abnormality is hypertriglyceridemia followed by hypercholesterolemia.
