Also see Physical Exam

Bony

• fibrous dysplasia: McCune Albright
• bowing of bones: OI
• skull: wormian bones: OI
• stippling of uncalcified epiphyses which disappears after first year of life: coumadin syndrome

Radiology

• Beads on a string: Sclerosing cholangitis, fibromuscular dysplasia
• Intusseption: Ultrasound/XR
  1. Target Sign (akaDoughnut, Bull’s Eye): RUQ, just below the liver. Due to layers of peritoneal fat surrounding and within the intussusception alternating with layers of mucosa.
  2. Crescent Sign: Soft-tissue density in LUQ projecting into the colon (leading edge).
  3. Absent Liver Edge Sign: Liver not easily identified.
• String sign on upper GI: pyloric stenosis
• Leukemic lines (lucent lines at the metaphyses of long bones): Leukemia
• megaesophagus and bird beak sign on UGI: achalasia

Neurophysiologic

• EEG: centrotemporal spikes: benign rolandic epilepsy
• EEG: hypsarrhythmia: infantile spasms

Microscopic

• acanthocytes (>50% in a nbn, w/ retic 10-20%): infantile pyknocytosis
• isolated thrombocytopenia: TAF (if also w/ absent thumb)
• small platelets: Wiscott-Aldritch
• large platelets: Bernard-Soulier
• drop of blood exposed to air has a chocolate hue: methemoglobinemia

Labs: CSF

• albuminocytologic dissociation: high protein, low WBC in Guillain Barre. Cerebrospinal fluid protein levels are elevated in 50% of patients during the first week of illness and in many more patients following the first week.