LEPROSY

Question 1

TRUE OR FALSE: M. leprae is an obligate, intracellular, acid-fast staining, rod-shaped bacterium

Answer 1

TRUE

Question 2

It is the measure of uniformly stained solid bacilli on slit-skin smear examination and is calculated as the percentage of viable bacilli among the total number of bacilli counted under oil-immersion microscopy

Answer 2

morphologic index

Question 3

It is a logarithmic-scaled measure of the density of bacilli of all forms found in the dermis upon slit skin smear examination, varying from 0 to 6+ (with or without globi) from the tuberculoid to the lepromatous end of the disease spectrum.

Answer 3

bacteriologic index

Question 4

M. leprae infects mainly what cells?

Answer 4

macrophages and Schwann cells

Question 5

What is the definition of leprosy elimination according to the WHO?

Answer 5

prevalence of <1 case per 10,000 population at the global level

Question 6

Mode of transmission of M. leprae

Answer 6

Can be shed in large numbers from the mouth and nose of patients with untreated multibacillary leprosy (droplet infection) and sometimes from damaged skin

Question 7

Main reservoir of M. leprae

Answer 7

HUMANS are the main reservoir of infection for M. leprae

• Armadillo is also a reservoir for human infection

Question 8

Incubation period of M. leprae

Answer 8

2 years to 10 years

• Incubation period for multibacillary leprosy appears to be longer (5 to ≥10 years) than that for paucibacillary leprosy (~2–5 years)

Question 9

The most important risk factors for the transmission of leprosy?

Answer 9

Intimacy and duration of contact with a leprosy patient

*in particular with an index case with multibacillary leprosy, and the intensity of contact with and physical distance from the index patient

Question 10

According to the WHO leprosy classification, this is defined as one to five skin lesions and no or only one involved peripheral nerve

Answer 10

Paucibacillary leprosy

Question 11

According to the WHO leprosy classification, this is defined as six or more skin lesions and/or more than one involved peripheral nerve.

Answer 11

Multibacillary leprosy

Question 12

This type of leprosy is characterized by either a well-defined, hypopigmented macule or a raised, erythematous/ brown/copper-colored plaque with a well-defined edge on any part of the skin with complete loss of fine touch and temperature sensations over their surface. On slit-skin smear examination, no acid-fast bacilli (AFB) are normally found. The lepromin skin test is strongly positive, signifying good host CMI status.

Answer 12

Tuberculoid leprosy

Question 13

This type of leprosy has innumerable bilateral, symmetrically distributed, diffusely indurated, erythematous, copper-colored, or skin-colored patches or plaques. There is no loss of sensation over these lesions, which have a smooth, shiny surface. The lesions are spread over the face, earlobes, ears, extensor aspects of the upper and lower extremities, back, and buttocks. Slit-skin smear examination shows a bacteriologic index of 4+ to 6+ with globi

Answer 13

Lepromatous Leprosy

Question 14

It is an immunologic phenomena that occur before, during, or after treatment. In addition, it has severe complications that need to be diagnosed and treated early to prevent nerve function impairment

Answer 14

Leprosy reactions

Question 15

This is a delayed hypersensitivity reaction associated with sudden alteration of CMI status and leading to a shift in the patient’s position on the leprosy spectrum. Also known as reversal reaction

Answer 15

Type 1 Leprosy reaction

Question 16

It is also known as ENL (erythema nodosum leprosum). It is an immune complex–mediated syndrome (i.e., an antigen–antibody reaction involving complement) that causes inflammation of the skin, nerves, and other organs as well as general malaise

Answer 16

Type 2 Leprosy reaction

Question 17

What are the three cardinal signs that indicate a diagnosis of leprosy

Answer 17

1) Hypopigmented or erythematous skin lesion(s) with definite loss or impairment of sensation
2) Involvement of the peripheral nerves, as demonstrated by definite thickening with sensory impairment
3) A positive result for AFB in slit-skin smears, establishment of the presence of AFB in a skin smear or biopsy sample, or a positive result in a biopsy PCR.

Question 18

Sites for slit skin smear test?

Answer 18

Slit-skin smear is taken from four sites
* the right earlobe
* the forehead above the eyebrows
* the chin
* the left buttock in men or the left upper thigh in women

Question 19

WHO-recommended multidrug therapy for multibacillary leprosy

Answer 19

MONTHLY dose of RIFAMPIN together with DAILY doses of DAPSONE and DAILY and MONTHLY doses of CLOFAZIMINE. A total of 12 months treatment for multibacillary disease

Question 20

Treatment for paucibacillary leprosy?

Answer 20

MONTHLY doses of RIFAMPIN and DAILY doses of DAPSONE x 6 months duration

Question 21

The most noticeable adverse event of this drug is skin discoloration ranging from red to purple or black, with the degree of discoloration depending on the dosage

Answer 21

CLOFAZIMINE

Question 22

Treatment of choice for type 1 Leprosy reaction

Answer 22

Oral, short-acting glucocorticoids are the treatment of choice for T1R.

• Prednisolone is used most often in an initial dose of 1 mg/kg of body weight once a day, usually with a maximum of 60–80 mg
• an initial dose of 40 mg of prednisolone is recommended by the WHO.
  *dose is tapered slowly, usually by 5 mg every 2 weeks over a period of 20 week

Question 23

Mild first-time T2R (or ENL) reactions with localized skin nodules may be treated with

Answer 23

aspirin and pentoxifylline

Question 24

If a rapid effect is needed, the most effective drug to date for T2R is?

Answer 24

Thalidomide

• rapidly suppresses clinical signs, including nerve impairment and iritis
• A dose of 100–200 mg is given either once or twice daily
• tapered down and stopped after 1–2 weeks

Question 25

TRUE OR FALSE: In multibacillary leprosy, relapse is defined as the multiplication of M. leprae, with an increase of at least 2+ over the previous value in the bacteriologic index at any single site

Answer 25

TRUE

Question 26

TRUE OR FALSE: Patients with relapse can be re-treated with the same multibacillary regimen.

Answer 26

TRUE

Question 27

TRUE OR FALSE: Recognizing a relapse in paucibacillary leprosy can be difficult, as symptoms may resemble a Type 2 leprosy reaction.

Answer 27

FALSE. It resembles a type 1 reaction * Administration of a therapeutic trial with glucocorticoids to patients with new lesions may help distinguish between these two phenomenon * definite improvement within 4 weeks of initiation of glucocorticoid therapy indicates T1R, whereas a lack of response favors the diagnosis of a clinical relapse

Question 28

What is the treatment of choice for rifampin resistant leprosy?

Answer 28

Daily treatment with at least two second-line drugs—clarithromycin, minocycline, or a quinolone (ofloxacin, levofloxacin, or moxifloxacin)—plus clofazimine for 6 months, followed by clofazimine plus one of the second-line drugs daily for an additional 18 months

Question 29

Which of the following statements regarding the transmission of leprosy is true? A) Leprosy is primarily spread through contaminated water. B) Transmission occurs via droplet infection from untreated multibacillary patients. C) Fecal-oral transmission is the most common route. D) Leprosy is highly contagious and spreads rapidly in the general population.

Answer 29

Correct Answer: B) Transmission occurs via droplet infection from untreated multibacillary patients. Rationale: M. leprae is mainly transmitted through prolonged close contact with untreated multibacillary patients, where the organism is shed in large numbers from the nose and mouth. Contrary to common belief, leprosy is not highly contagious, and many exposed individuals do not develop the disease due to genetic resistance and immune response.

Question 30

Which of the following is a key diagnostic criterion for leprosy? A) Presence of cavitary lung lesions on chest X-ray B) Hypopigmented or erythematous skin lesions with sensory impairment C) Gram-positive cocci on skin biopsy D) Sudden onset of fever and joint pain

Answer 30

Correct Answer: B) Hypopigmented or erythematous skin lesions with sensory impairment Rationale: Leprosy is diagnosed clinically based on three cardinal signs: (1) hypopigmented or erythematous skin lesions with definite sensory impairment, (2) thickened peripheral nerves with sensory/motor impairment, and (3) acid-fast bacilli on slit-skin smear or biopsy. Other options describe symptoms of unrelated diseases like tuberculosis or bacterial infections.

Question 31

According to WHO classification, how is multibacillary leprosy distinguished from paucibacillary leprosy? A) Presence of six or more skin lesions and/or more than one involved peripheral nerve B) Presence of a positive tuberculin skin test C) Presence of acid-fast bacilli in blood samples D) Detection of M. leprae DNA in saliva samples

Answer 31

Correct Answer: A) Presence of six or more skin lesions and/or more than one involved peripheral nerve Rationale: WHO classifies leprosy into multibacillary (MB) and paucibacillary (PB) based on clinical and laboratory findings. MB leprosy is characterized by six or more skin lesions and/or multiple affected nerves, often with a positive slit-skin smear for M. leprae. PB leprosy has fewer lesions and no/slightly affected nerves.

Question 32

What is the primary mode of action of rifampin in the treatment of leprosy? A) Inhibition of DNA gyrase B) Inhibition of mycolic acid synthesis C) Inhibition of RNA polymerase D) Disruption of folic acid synthesis

Answer 32

Correct Answer: C) Inhibition of RNA polymerase Rationale: Rifampin acts by inhibiting DNA-dependent RNA polymerase, thereby preventing bacterial RNA synthesis. It is a key component of multidrug therapy for leprosy, effectively killing M. leprae. Other drugs like dapsone (which inhibits folic acid synthesis) and clofazimine are also used in combination therapy.

Question 33

Which of the following is a major adverse effect associated with dapsone therapy in leprosy treatment? A) Hepatotoxicity B) Neurotoxicity C) Hemolysis D) Nephrotoxicity

Answer 33

Correct Answer: C) Hemolysis Rationale: Dapsone, an anti-folate drug used in leprosy treatment, can cause hemolysis, particularly in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Severe reactions, including Dapsone Hypersensitivity Syndrome, may also occur.

Question 34

Which of the following best describes Lepromatous leprosy (LL)? A) Few, well-defined, hypopigmented macules with complete loss of sensation B) Bilateral, numerous erythematous plaques with symmetrical distribution C) A single lesion with satellite macules D) Thickened peripheral nerves with no skin involvement

Answer 34

Correct Answer: B) Bilateral, numerous erythematous plaques with symmetrical distribution Rationale: Lepromatous leprosy is characterized by widespread, symmetrically distributed plaques or nodules, often affecting the face, ears, and extremities. Unlike tuberculoid leprosy, sensation is usually intact initially, and a high bacterial load is observed.

Question 35

What is the primary treatment for Type 1 leprosy reactions (T1R)? A) Antihistamines B) Prednisolone C) Rifampin D) Clofazimine

Answer 35

Correct Answer: B) Prednisolone Rationale: Type 1 leprosy reactions (T1R) are delayed hypersensitivity reactions that cause inflammation of skin lesions and nerves. Corticosteroids, such as prednisolone, are the first-line treatment to reduce inflammation and prevent nerve damage.

Question 36

Which of the following statements regarding the relapse of leprosy is correct? A) Relapse of paucibacillary leprosy is common and requires re-treatment with multidrug therapy. B) Multibacillary leprosy relapse is identified by an increase in the bacteriologic index by at least 2+ at a single site. C) Leprosy relapse usually occurs within one year of completing treatment. D) A new skin lesion always indicates relapse.

Answer 36

Correct Answer: B) Multibacillary leprosy relapse is identified by an increase in the bacteriologic index by at least 2+ at a single site. Rationale: In MB leprosy, relapse is diagnosed when the bacteriologic index increases by at least 2+ over a prior measurement at any single site, typically along with clinical deterioration. PB leprosy relapse is rare, and new lesions could indicate a reaction rather than true relapse.