hair-on-end appearance

hair-on-end appearance

Crewcut appearance Imaging A radiologic pattern seen as calcified spicules perpendicular to bone surface, corresponding to a periosteal reaction to disturbed bone repair with neoosteogenesis of the outer cranial table, marked calvarial thickening, external displacement and thinning of the inner table; classically seen in children/adolescents with thalassemia DiffDx Periostitis of long bones in congenital syphilis–syphilitic periosteitis of tibia, giving rise to Saber shins, see there, congenital hemolytic anemias–pyruvate kinase deficiency, hereditary elliptocytosis and spherocytosis, sickle cell anemia, metastatic neuroblastoma, iron-deficiency anemia, cyanotic–right-to-left shunt congenital heart disease, osteomyelitis, polycythemia vera, thyroid acropachy, hemangiomas