Makindo Medical Notes

🌐 Erythema Gyratum Repens (EGR) is a rare paraneoplastic dermatosis with striking, rapidly migrating concentric bands that resemble wood grain. 🧠 It is most strongly associated with lung cancer but can signal other internal malignancies. ⚠️ Recognising this rash is important as it may be the first visible clue to an occult neoplasm.

📖 About

• Definition: A skin disorder with red, ring-like lesions forming concentric “wood-grain” patterns.
• Epidemiology: < 100 cases in the literature. Seen mainly in middle-aged/older adults, slightly more in men.

🩺 Clinical Features

• Appearance: Migrating erythematous bands, advancing several cm per week.
• Pattern: Concentric rings with clear central zones.
• Symptoms: Often itchy or burning, but systemic symptoms usually relate to underlying cancer.
• Distribution: Commonly trunk and proximal limbs, often covering large body areas.

⚡ Causes

• Paraneoplastic: Most often linked with:
  • 🫁 Lung carcinoma (esp. squamous cell)
  • 🧪 Oesophageal carcinoma
  • 🎗️ Breast & ovarian cancers
  • Occasionally with unknown primaries
• Non-malignant associations (rare): Infections, autoimmune disease, inflammatory conditions.

🔎 Investigations

• Clinical exam: Classic rash may be diagnostic if typical.
• Imaging: Chest X-ray/CT, abdo ultrasound/CT for hidden malignancy.
• Biopsy: Non-specific (parakeratosis, acanthosis, dermal inflammation), used mainly to exclude other dermatoses.
• Bloods: Tumour markers, baseline haematology/biochemistry.
• Endoscopy: If oesophageal involvement suspected.

💊 Management

• Treat underlying malignancy: Resolution often parallels successful cancer therapy.
• Symptomatic care:
  • Topical corticosteroids for inflammation.
  • Antihistamines for itch.
  • Emollients for skin barrier support.
• Ongoing surveillance: If no cancer is initially found, patients require close follow-up, as EGR can precede tumour diagnosis by months.

📉 Prognosis

• Strongly associated with advanced malignancy, thus prognosis depends on underlying cancer stage.
• Skin lesions often resolve if the tumour is treated successfully.

📚 References

• Case Report & Literature Review – EGR
• DermNet NZ
• Merck Manual – EGR
• AAFP – Paraneoplastic Syndromes