What are the long-term complications of untreated leishmaniasis?

Long-Term Complications of Untreated Leishmaniasis

Untreated leishmaniasis can lead to severe complications including disfiguring scarring, chronic wounds, destructive mucosal lesions, and potential dissemination in immunocompromised individuals, with the specific complications varying by species and clinical form. 1

Types of Leishmaniasis and Their Complications

Cutaneous Leishmaniasis (CL) Complications

• Persistent lesions and scarring:

  • Untreated lesions may persist for 2-15 months depending on the species 1
  • Extensive scarring and pigmentary changes, especially on the face, causing substantial aesthetic impact 1
  • Poor cosmetic outcomes leading to psychological, social, and economic problems, particularly affecting women 2

• Superinfection of lesions:

  • Secondary bacterial infections of open wounds 1
  • Chronic non-healing wounds that may persist for years 1

• Progression to complex forms:

  • Diffuse cutaneous leishmaniasis (DCL): Rare complication seen with L. mexicana, L. amazonensis, L. venezuelensis, and L. pifanoi 1
  • Disseminated cutaneous leishmaniasis: Multiple widespread lesions 1
  • Leishmaniasis recidivans: Chronic relapsing form with lesions that heal and recur 1

Mucosal Leishmaniasis (ML) Complications

• Destructive mucosal lesions:
  • Primarily associated with Viannia species from Costa Rica and further south 1
  • Can develop months to years after initial cutaneous infection 1
  • Destructive lesions of the nasal, oral, pharyngeal, and laryngeal mucosa 1
  • Symptoms include nasal stuffiness, epistaxis (nosebleeds), hoarseness, and septal perforation 1
  • Advanced ML is difficult to treat with unsatisfactory outcomes 1

Visceral Leishmaniasis (VL) Complications

• Fatal outcome:
  • Almost all untreated cases of visceral leishmaniasis are fatal 3
  • Dissemination throughout the reticuloendothelial system 1

Risk Factors for Severe Complications

Species-Dependent Risk

• High risk for mucosal disease:

  • Leishmania (Viannia) braziliensis and related Viannia species from Costa Rica southward 1
  • Risk for ML is highest within 2 years of initial cutaneous infection 1

• Lower risk species:

  • L. major (spontaneous healing in 2-6 months)
  • L. mexicana (spontaneous healing in 3-9 months)
  • L. tropica, L. (V.) braziliensis, L. (V.) panamensis (spontaneous healing in 6-15 months) 1

Host-Dependent Risk

• Immunocompromised status:
  • Significantly higher risk for:
    • Parasite dissemination
    • Clinical polymorphism with atypical and more severe forms
    • Visceralization of cutaneous forms
    • Treatment failure and relapse 4
  • HIV co-infection particularly increases severity and mortality 4

Monitoring and Prevention of Complications

• Follow-up recommendations:

  • Active clinical monitoring including nasal and oropharyngeal examinations for up to 1 year
  • Extended monitoring for at least 2 years in patients at increased risk for ML 1
  • Patient education about signs and symptoms of relapse and ML 1

• Warning signs requiring immediate evaluation:

  • Chronic nasal stuffiness
  • Epistaxis (nosebleeds)
  • Hoarseness
  • Septal perforation 1

Treatment Considerations to Prevent Complications

• Systemic therapy indications:

  • Complex cutaneous leishmaniasis
  • Infections with high risk for mucosal involvement (Viannia species from Costa Rica southward)
  • Diffuse cutaneous leishmaniasis, disseminated cutaneous leishmaniasis, and leishmaniasis recidivans
  • Immunocompromised patients 1

• Local therapy or observation considerations:

  • May be appropriate for simple lesions with low risk for complications
  • Appropriate for infections acquired in regions where ML is rare
  • Should be followed by systemic therapy if lesions do not heal 1, 5

By understanding the potential long-term complications of untreated leishmaniasis and the risk factors associated with severe disease, healthcare providers can make informed decisions about treatment to prevent these complications and improve patient outcomes.