Title: GZ / The Grenz Zone Season 2 / 31 Retiform Purpura
Tags: GZ DermnetNZ

Q: Retiform Purpura is due to complete blockage of [2 answers] leading to skin infarction and hemorrhage
A: dermal and subQ vessels
Back Extra: Clinical sign hinting toward an underyling medical condition
This type of purpura has more of an angulated shape

Q: Is retiform purpura a clinical sign or a diagnosis?
[...]
A: Clinical sign

Differential diagnosis presenting with retiform purpura can be remembered by the pneumonic ADVICE:
A: Anti-phospholipid syndrome
D: Drugs (heparin & coumadin)
V: Vasculitis or Vasculopathies
I: Infections
C: Calciphylaxis or Cocaine tainted with levamisole
E: Emboli (cholesterol or fat)
Back Extra: Infections include: meningococcemia(N. meningitides), echthyma gangrenosum (Pseudomonas), necrotizing fasciitis (group A strep, Clostridium), angioinvasive fungi (Aspergillus), disseminated strongyloidiasis, and brown recluse spider bites
Retiform purpura due to cholesterol emboli
Retiform purpura due to calciphylaxis
Retiform purpura due to vasculitis

Q: Clinically, retiform purpura (branching purpura) presents as a hot neon pink to [color] angulated lesion that is tender to touch and favors dependent areas (e.g. [body area])
A: dark black-purple; lower legs
Back Extra: Associated with hemorrhagic bullae or ulcers within distribution

Q: Livedo reticularis is due to [...], vascular wall inflammation, or [early or late] obstruction
A: vasospasm; early

Q: Clinically, livedo reticularis presents as erythema in a completely-connected [specific pattern], usually on the extremities
A: netlike pattern

Q: Livedo Racemosa presents similarly to livedo reticularis, but without [...] netlike connection
A: complete
Back Extra: Livedo Racemosa

Q: What would be in your differential if the lesions of retiform purpura are inflamed or palpable?
[...]
A: Vasculitis
Back Extra: Inflammatory Retiform Purpura

Q: If the lesions of retiform purpura are distributed symmetrically on the upper & lower extremities, what would be in your differential?
[...]
A: DIC

Q: If the lesions of retiform purpura are focused on the fatty areas (e.g. thighs or lower abdomen), what would be in your differential?
[2 answers]
A: Calciphylaxis or coumadin necrosis

Q: If the lesions of retiform purpura are located on cooler areas (e.g. ears or digits), what would be in your differential?
[2 answers]
A: Cryoglobulinemia or levamisole-tainted cocaine

Q: If lesions of atrophie blanche are present in the setting of retiform purpura, what would be in your differential?
[...]
A: Anti-phospholipid syndrome
Back Extra: Atrophie blanche: white, angulated scarred plaque with surrounding inflammation on the lower extremity

Q: If a patient had a recent heart catheterization and is now presenting with retiform purpura, what would be in your differential?
[...]
A: Cholesterol embolism

Q: If a patient has recently broken their hip and is now presenting with retiform purpura, what would be in your differential?
[...]
A: Fat emboli

Q: Diagnosis of the underlying cause of retiform purpura includes [...] and [...]
A: labs; biopsy
Back Extra: Labs include: CBC, CMP, Coagulation profile, Sed rate, CRP, UA, Drug Tox Screen
Biopsy: Excisional vs double-punch (1 at the center of lesion & 1 at the edge of lesion)

Q: How do you treat retiform purpura?
[broad]
A: Treat underlying cause
Back Extra: - Anti-phospholipid ab syndrome = Anticoagulation
- Drugs = Heparin Necrosis = Stop Heparin + alternative anticoagulant (e.g. argatroban); Coumadin Necrosis = Stop Coumadin + alternative anticoagulation + Vitamin K or Fresh Frozen Plasma
- Vasculitis = Systemic anti-inflammatory medications (e.g. prednisone) or steroid-sparring agent (e.g. methotrexate)
- Vasculopathy = Consult Hematology
- Infectious = Bacteria: antibiotics; Fungal: anti-fungals; Parasite: anthelmintics; Brown recluse: supportive + wound care
- Calciphylaxis = IV sodium thiosulfate + correction of serum calcium, phosphate, parathyroid hormone levels
- Cocaine = Stop drug use
- Emboli = Cholesterol: Supportive CV measures + surgical intervention; Fat: Repair long bone fx +/- IVC filter or corticosteroids