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December iotaderma (#274)
JAAD ONLINE: IOTADERMA IOTADERMA #275 To what does the splendiferous term ‘‘cheiroarthropathy’’ refer, and in what sorts of patients would we as dermatologists encounter it? Robert I. Rudolph, MD, FACP Answer will appear in the JAAD Online section of the February issue of the Journal.
DECEMBER IOTADERMA (#274) If you encountered a patient who mentioned that they had been told that they had ‘‘hairs on end’’ and a ‘‘funny thick skull,’’ what does this mean, and what should you avoid? Answer: The patient is telling you that they have a hemolytic anemia of some sort!1-4 In patients with these diseases, noncontrast computed tomography scans of the head reveal a thickening of the calvarium with perpendicular proliferation of the skull trabeculae, which has been designated the ‘‘hair on end’’ sign.1 This radiologic finding can be seen in the context of many hemolytic anemias, such as sickle cell disease, thalassemia major, and (most important for dermatologists) glucose-6-phosphate dehydrogenase deficiency.2-4 The bony changes are a result of the red bone marrow proliferating, eventuating in alternating thickened and opaque trabeculae with radiolucent marrow hyperplasia.1,4 If the patient is unlucky enough to be diagnosed as also having dermatitis herpetiformis, remember to not reflexively prescribe dapsone—giving it to them would cause catastrophic, dose-related hemolysis. REFERENCES 1. Watanabe M, Saito N, Nadgir RN, et al. Craniofacial bone infarcts in sickle cell disease: clinical and radiological manifestations. J Comput Assist Tomogr. 2013;37:91-97. 2. Martin L, Rackard F. Images in clinical medicine. Hair-on-end sign. N Engl J Med. 2016;374:e23. 3. Bickle I, Weerakkody Y. Hair on end sign. Available at: http://radiopaedia.org/ articles/hair-on-end-sign. Accessed August 10, 2016. 4. Ramirez I, Chew FS, Asrat W, et al. Sickle cell anemia skeletal imaging. Available at: http://emedicine.medscape.com/article/413542-overview. Accessed August 10, 2016.
Robert I. Rudolph, MD, FACP
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DECEMBER IOTADERMA (#274) If you encountered a patient who mentioned that they had been told that they had ‘‘hairs on end’’ and a ‘‘funny thick skull,’’ what does this mean, and what should you avoid? Answer: The patient is telling you that they have a hemolytic anemia of some sort!1-4 In patients with these diseases, noncontrast computed tomography scans of the head reveal a thickening of the calvarium with perpendicular proliferation of the skull trabeculae, which has been designated the ‘‘hair on end’’ sign.1 This radiologic finding can be seen in the context of many hemolytic anemias, such as sickle cell disease, thalassemia major, and (most important for dermatologists) glucose-6-phosphate dehydrogenase deficiency.2-4 The bony changes are a result of the red bone marrow proliferating, eventuating in alternating thickened and opaque trabeculae with radiolucent marrow hyperplasia.1,4 If the patient is unlucky enough to be diagnosed as also having dermatitis herpetiformis, remember to not reflexively prescribe dapsone—giving it to them would cause catastrophic, dose-related hemolysis. REFERENCES 1. Watanabe M, Saito N, Nadgir RN, et al. Craniofacial bone infarcts in sickle cell disease: clinical and radiological manifestations. J Comput Assist Tomogr. 2013;37:91-97. 2. Martin L, Rackard F. Images in clinical medicine. Hair-on-end sign. N Engl J Med. 2016;374:e23. 3. Bickle I, Weerakkody Y. Hair on end sign. Available at: http://radiopaedia.org/ articles/hair-on-end-sign. Accessed August 10, 2016. 4. Ramirez I, Chew FS, Asrat W, et al. Sickle cell anemia skeletal imaging. Available at: http://emedicine.medscape.com/article/413542-overview. Accessed August 10, 2016.
Robert I. Rudolph, MD, FACP
e41