Rhinosporidiosis ent

Rhinosporidiosis

Definition: A chronic granulomatous disease caused by Rhinosporidium seeberi affecting both humans and animals.

Epidemiology

  • Global: Most cases from India, Sri Lanka, Pakistan.
  • Reported in: Africa (Kenya, Tanzania, Rwanda, Burkina Faso, Chad, Egypt), South America (Argentina, Brazil), N. America, Europe.
  • Negative Finding: No case reported from Australia.
  • In India: Prevalent in Southern states (TN, Kerala, Andhra, Puducherry) and Central (MP, Chhattisgarh). Rare in Punjab/Haryana.
  • Hosts: Man and Animals (Cows, bulls, horses, mules, dogs).
  • Transmission: Sharing infected ponds with animals.

Aetiology: The Organism

  • Status: Difficult to classify. NOT cultured so far.
  • Classification: Considered a protozoan or fish parasite of the DRIP clade:
    • Dermocystidium
    • Rosette agent
    • Ichthyophonus
    • Psorospermum

Life Cycle (3 Stages)

1. Trophic Stage

  • Endospore: Oval/rounded, 6–8 µm.
  • Structure: Clear cytoplasm, vesicular nucleus with nucleolus, chitinous covering.
  • Growth: Increases in size; nuclear/cytoplasmic division forms young endospores (Trophocyte).

2. Development of Sporangium

  • Size: 200–250 µm diameter.
  • Content: 12,000–16,000 endospores.
  • Wall: Thick, two layers (Outer Chitinous, Inner Cellulose).
  • Maturation: Formation of mucoid/chitinous wall + Germinal Pore (ready to burst).

3. Production of Endospores

Mechanism Outcome
High Internal Pressure Rupture of sporangium → liberation of spores into tissue.
Low Pressure Spores liberated one by one without breaking wall.
Lymphatic Spread Endospores carried to bloodstream → Disseminated disease.

Clinical Features

Sites: Nose & Nasopharynx (Main). Others: Lip, palate, conjunctiva, larynx, trachea, skin, genitalia.

The Nasal Mass:
  • Leafy, polypoidal, pink-to-purple.
  • Attached to septum or lateral wall.
  • Can hang behind soft palate (Nasopharynx).
  • Vascularity: Bleeds easily on touch.
  • Diagnostic Sign: Surface studded with white dots (Sporangia).

Symptoms: Nasal discharge (blood-tinged), stuffiness, frank epistaxis.

Diagnosis & Treatment

Diagnosis

  • Biopsy: Shows sporangia (oval/round) filled with spores; some bursting through chitinous wall.
  • Culture/Animal Transfer: Not possible.

Treatment

Surgery: Complete excision with Diathermy knife + Cauterization of base.
Warning: Recurrence may occur after excision.
  • Medical: Not many drugs effective. Dapsone used with some success.
📚 Source: ENT Dhingra

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