Updated: 6/6/2018

Leprosy

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
1
0
0
0%
0%
Evidence
2
0
0
Topic
Snapshot
  • A 50-year-old woman presents to her primary care physician for a rash. She describes her past year of backpacking throughout the world including multiple areas of Southeast Asia. She states that her face feels thicker than normal and that she has developed a rash throughout her body. On physical exam, she has leonines facies with thickened earlobes, cheeks, and eyebrows. There are also diffuse nodular and plaque-like lesions with hypopigmentation and non-defined borders. She is counselled on the need for long-term antibiotics.
Introduction
  • Classification
    • Mycobacterium leprae
      • a non-motile acid-fast bacillus
      • prefers cool temperatures
    • transmission
      • respiratory via nasal mucosa
      • via armadillo reservoirs
  • Epidemiology
    • incidence
      • more common in Southeast Asia and South America
    • location
      • affects skin and peripheral nerves
    • risk factors
      • travel to endemic countries
      • contact with others with leprosy
      • contact with or consumption of reservoirs such as armadillos
  • Pathogenesis
    • the bacteria grows in cool regions, such as the skin and peripheral nerves
    • infects macrophages, Schwann cells, and keratinocytes
    • lepromatous Hansen disease
      • weak cell-mediated immunity
      • humoral Th2-type immune response
      • high burden of bacteria in lesions
    • tuberculoid Hansen disease
      • strong cell-mediated immunity
      • Th1-type immune response
      • low burden of bacteria in lesions
  • Associated conditions 
    • lepromatous Hansen disease
    • tuberculoid Hansen disease
    • erythema nodosum
  • Prognosis
    • slow progression that may develop over months or years
    • may have intermittent acute leprosy reactions
    • lepromatous type is more severe
Presentation
  • Symptoms
    • lepromatous Hansen disease
      • diffuse rash
    • tuberculoid Hansen disease
      • multiple discrete lesions
  • Physical exam
    • patients often present with overlapping findings
    • peripheral neuropathy
      • foot drop
      • facial nerve palsy
      • contractures or hand or feet
      • loss of sensation
    • lepromatous Hansen disease
      • leonine facies (lion-like)
        • thickened foreheard, ears, eyebrows, and cheeks
      • diffuse plaques and nodular skin lesions symmetrically distributed
        • may be erythematous or hypopigmented without sharp borders
    • tuberculoid Hansen disease
      • multiple discrete erythematous plaques with central hypopigmentation and raised discrete borders
        • plaques often have loss of sensation
        • hairless
        • dry with some scale
Studies
  • Labs
    • tissue polymerase chain reaction (PCR)
    • may test as falsely positive on VDRL testing
  • Biopsy or slit-skin smear
    • acid-fast bacilli
    • granulomas
  • Making the diagnosis
    • based on clinical presentation and tissue diagnosis
Differential
  • Morphea
    • distinguishing factor
      • also presents with thickened skin but usually does not involve peripheral nerve damage
  • Vitiligo
    • distinguishing factor
      • also presents with hypopigmentation but without peripheral nerve damage or raised borders
Treatment
  • Medical
    • dapsone and rifampin
      • indication
        • tuberculoid and lepromatous types
    • clofazimine
      • indication
        • added therapy for lepromatous types
Complications
  • Permanent nerve impairment
  • Deformities

Please rate topic.

Average 5.0 of 4 Ratings

Questions (1)

(M2.ID.15.45) A 45-year-old non-English-speaking, Asian male presents to your office. He shows you a lesion on his elbow (Figure A). He has been having decreased sensation in that area and now cannot feel sharp pinpricks on your physical exam. The lesion is biopsied (Figure B). Which of the following is the most likely diagnosis?

QID: 104930
FIGURES:
1

Tinea corporis

0%

(0/20)

2

Tuberculoid leprosy

45%

(9/20)

3

Lepromatous leprosy

40%

(8/20)

4

Sarcoidosis

5%

(1/20)

5

Mycosis fungoides

5%

(1/20)

M 6 E

Select Answer to see Preferred Response

Evidence (2)
EXPERT COMMENTS (3)
Private Note