Pseudoxanthoma Elasticum

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Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum is an autosomal recessive connective tissue disorder caused by mutation of the ABCC6 gene encoding ATP binding cassette subfamily C member 6, resulting in progressive calcification and fragmentation of elastic fibers in skin, eyes, and blood vessels. Cutaneous manifestations include thin yellowish papules that commonly arise on the lateral neck and other flexural areas such as the axillae, groin, wrists, and periumbilical skin, which can coalesce into cobblestone plaques resembling plucked chicken skin. In advanced disease, dermal calcium deposition and transepidermal elimination of calcified elastic fibers may produce perforating pseudoxanthoma elasticum. Ocular findings include angioid streaks caused by rupture of Bruch membrane and may be accompanied by hyperpigmented spots along the streaks that create an owl eye appearance. Angioid streaks are also associated with Paget disease of bone, Ehlers Danlos syndrome, sickle cell anemia, thalassemia, and lead poisoning. Cardiovascular complications include hypertension, mitral valve prolapse, angina, myocardial infarction, and stroke. Gastrointestinal involvement may cause gastric artery hemorrhage. Obstetric complications include increased risk of first trimester miscarriage. Histopathology demonstrates basophilic fragmented and calcified elastic fibers located in the mid to deep reticular dermis.

Genetics

  • Selling Cassettes = ABCC6 gene mutation

Cutaneous Findings

  • Yellow Twinkie Crumbs On Neck And Elbows = Thin yellowish papules in flexural areas
  • Chicken On Cobblestone Ground = Cobblestone plaques resembling plucked chicken skin
  • Calcium Milk Gallon Extruding Milk = Increased dermal calcium deposition and perforating pseudoxanthoma elasticum

Ocular Findings

  • Oil Spill With Red Oil Streaks = Ocular angioid streaks from Bruch membrane rupture
  • Broke Oil Container = Bruch membrane rupture
  • Hyperpigmented Owl = Owl eye appearance of hyperpigmented spots straddling angioid streaks

Associated Conditions With Angioid Streaks

  • Beauty Pageant Queen Holding Bone = Paget disease of bone
  • Flexible Beauty Pageant Queen = Ehlers Danlos syndrome
  • Maintenance Worker With Sickle Shaped Tool = Sickle cell anemia
  • Microcytic Target Stickers = Thalassemia microcytic anemia and target cells
  • Rusty Lead Pole = Lead poisoning

Cardiovascular Findings

  • High Pressure Steam From Gas Tank = Hypertension
  • Pope Wearing Mitre Hat = Mitral valve prolapse
  • Pope Clutching Chest = Angina and myocardial infarction
  • Black Stroke Of Paint On Head = Stroke

Gastrointestinal Findings

  • Red Gas Leak From Broken Gas Line = Gastric artery hemorrhage

Obstetric Complications

  • Pregnant Woman Holding Empty Carriage = First trimester miscarriage

Histology

  • Purple Elastic Bands Covered In Calcium Milk = Basophilic fragmented calcified elastic fibers in the mid to deep reticular dermis

Quiz

Question 1
Which gene mutation is responsible for pseudoxanthoma elasticum?

A. COL7A1
B. ABCC6
C. FBN1
D. ATP2A2

Question 2
What is the classic cutaneous lesion seen in pseudoxanthoma elasticum?

A. Violaceous polygonal papules
B. Thin yellowish papules in flexural areas
C. Pearly nodules with telangiectasias
D. Targetoid erythematous plaques

Question 3
Angioid streaks in pseudoxanthoma elasticum result from rupture of which structure?

A. Descemet membrane
B. Bruch membrane
C. Bowman membrane
D. Internal limiting membrane

Question 4
Which histologic finding is characteristic of pseudoxanthoma elasticum?

A. Suprabasal acantholysis
B. Spongiosis with eosinophils
C. Calcified fragmented elastic fibers in the reticular dermis
D. Granulomatous inflammation with giant cells

Question 5
Which of the following disorders is also associated with angioid streaks?

A. Neurofibromatosis type 1
B. Paget disease of bone
C. Dermatomyositis
D. Sarcoidosis

Question 6
Which cardiovascular abnormality is associated with pseudoxanthoma elasticum?

A. Aortic dissection
B. Mitral valve prolapse
C. Ventricular septal defect
D. Coarctation of the aorta

Question 7
Which gastrointestinal complication may occur in pseudoxanthoma elasticum?

A. Esophageal varices
B. Gastric artery hemorrhage
C. Pancreatitis
D. Ulcerative colitis

Answers:
1 B. ABCC6
2 B. Thin yellowish papules in flexural areas
3 B. Bruch membrane
4 C. Calcified fragmented elastic fibers in the reticular dermis
5 B. Paget disease of bone
6 B. Mitral valve prolapse
7 B. Gastric artery hemorrhage