RT Journal Article SR Electronic T1 Not what it seems JF Archives of disease in childhood - Education & practice edition JO Arch Dis Child Educ Pract Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP edpract-2019-318086 DO 10.1136/archdischild-2019-318086 A1 Eimear Anna McCorry A1 Art OHagan A1 Shilpa Shah YR 2019 UL http://ep.bmj.com/content/early/2019/10/30/archdischild-2019-318086.abstract AB A 5-month-old female patient presented to the general practitioner with a 2-week history of an unexplained linear lesion on her left lower limb extending from the medial part of her thigh to the medial aspect of her leg and onto the sole of her foot (figures 1 and 2). It was hyperpigmented, papular and non-blanching. There was no history of trauma, itching, pain, infective symptoms or social concerns. The baby was well kempt and parents were appropriately concerned.Figure 1 Linear lesion on the left leg.Figure 2 Linear lesion extending posteromedially to the left foot.QuestionsWhat is the diagnosis?Accidental imprint mark caused by car seat straps or seams of clothing.Inflicted injury caused by a linear object.Lichen striatus.Incontinentia pigmenti.­What is the common age of onset of these lesions?Present at birth.Appears within 2 weeks of life.Onset in early infancy.Onset between ages 5 and 15 years of life.QuestionsAnswers can be found on page 2.