We report on a 43-year-old Caucasian female who presented with bright red macules in a unilateral distribution in the left C5-8 and L3-5 dermatomes. Histopathologic examination showed superficial papillary dermal telangiectasia with minimal chronic inflammation. Immunohistochemical stains for estrogen and progesterone receptors (ER/PR) were negative. A diagnosis of unilateral nevoid telangiectasia syndrome (UNTS) was given. UNTS is an uncommon disorder first described by Alfred Blaschko in 1899. It is comprised of telangiectasias occurring in a predominantly unilateral dermatomal distribution and often affecting the trigeminal, cervical, and upper thoracic dermatomes. It can be either congenital or acquired and has a 2:1 female:male ratio. UNTS has been reported in relation to hyperestrogenic states, with half of the reported cases related to pregnancy, puberty, or liver disease. However, the vast majority of cases show no increase in estrogen and progesterone receptors in lesional skin. UNTS may be more common than previously believed, and shows some response to vascular laser therapy. Differential diagnoses include hemangioma, angioma serpiginosum, and rarely, nevus flammeus.