Figure 1.

(a) A lateral cervical spine radiograph of a 25‐year‐old woman (Patient 1) who was treated with acitretin and isotretinoin for lamellar ichthyosis, showing radiographic features of straightening of the normal cervical lordosis and anterior ossification from C3 to C7 (orange arrows), with appearances in keeping with skeletal hyperostosis. (b) An anterior thoracic spine radiograph of a 38‐year‐old woman (Patient 2) who was treated with isotretinoin for Darier disease, showing radiographic features of bridging osteophytes seen bilaterally (orange arrows) and anteriorly through the thoracic spine. (c) A lateral thoracolumbar spine radiograph of a 43‐year‐old woman (Patient 3) who was treated with isotretinoin for epidermolytic ichthyosis, with radiographic features showing diffuse syndesmophytosis with ossification of the anterior longitudinal ligament, with a linear longitudinal radiodense stripe also running centrally along the vertebral column (yellow arrow) in keeping with ossification of the interspinous/supraspinous ligaments with loss of the normal lumbar lordosis and in keeping with diffuse hyperostosis.