Combined clofazimine- and dapsone-resistant leprosy. A case report

Area of Science:

• Infectious Diseases
• Microbiology
• Dermatology

Background:

• Leprosy, a chronic infectious disease caused by Mycobacterium leprae, is typically treated with multidrug therapy.
• Dapsone monotherapy has been used historically, but resistance can emerge.
• Long-term clinical inactivity and bacterial negativity are markers of successful treatment.

Observation:

• A patient with lepromatous leprosy experienced a relapse after 23 years of dapsone monotherapy.
• The patient had achieved clinical inactivity and bacterial negativity during this period.
• Fresh skin lesions appeared during the relapse.

Findings:

• Mycobacterium leprae isolated from the patient's new lesions exhibited resistance to clofazimine.
• The bacteria also showed resistance to dapsone, the previously effective monotherapy agent.
• Standard mouse foot pad testing confirmed the drug resistance.

Implications:

• This case highlights the potential for Mycobacterium leprae to develop resistance to key antileprosy drugs even after prolonged treatment.
• Relapse with multidrug-resistant strains poses significant challenges for leprosy treatment and control.
• Further research into mechanisms of drug resistance and alternative therapeutic strategies is warranted.