This document discusses leprosy (Hansen's disease), caused by Mycobacterium leprae bacteria. It describes the classification systems for leprosy, including Ridley-Jopling and paucibacillary vs multibacillary. The typical skin lesions, nerve involvement, and systemic manifestations are outlined for each type of leprosy. Diagnosis involves identification of cardinal signs on skin or nerves, skin smears, and biopsy. Treatment involves multidrug therapy to prevent disability, while general measures focus on education, wound care, and counseling for treatment adherence. Untreated leprosy can cause permanent damage such as disfigurement, hair loss, muscle weakness, nerve damage, and eye complications.

1. DR SUBODH KUMAR SHAH

2.  Etiology
 Mycobacterium leprae (M. leprae), an acid fast organism.
 Route of infection : respiratory transmission.(droplets infection)

3. 1.Ridley–Jopling classification:
 Tuberculoid leprosy (TT)
 Borderline tuberculoid (BT)
 Mid borderline (BB)
 Borderline lepromatous (BL) leprosy
 Lepromatous leprosy (LL)
2.Skin smear result (WHO) classification :
 • 1- Paucibacillary leprosy (PB) – few Bacilli; • Two to five skin lesions with
negative skin smear results at all sites. •
 2. Multibacillary leprosy (MB); • Any form of leprosy in which the patient shows
positive smears at any site

5.  Prototype skin lesion: atrophic, hypopigmented, an(hypo)esthetic macules or plaques
(with papules and nodules seen in lepromatous end of spectrum) with loss of
appendages (so absent hair and sweating).
 Depending on number, size, symmetry, morphology and degree of sensory deficit in skin
lesions and numbers of nerves affected, classified as:
 Indeterminate leprosy: Ill-defined macule(always a macule) ± sensory impairment on
face of children.
 Tuberculoid leprosy (TT): Single (or few),well-defined anesthetic lesion(s). Regional
nerve(s)thickened.

6.  . Borderline tuberculoid (BT): Few, welldefined,hypoesthetic lesions with satellite
lesions.Few nerves involved.
 Borderline (BB): Multiple, bilateral(not symmetrical) annular plaques (inverted saucer
appearance) with hypoesthesia. Few nerves involved.
 Borderline lepromatous (BL): Multiple (with tendency to symmetry), minimally
hypoesthetic illdefined lesions. Many nerves (bilateral, tendency to symmetry) involved.
 Lepromatous leprosy (LL):Widespread symmetrical normoesthetic macules,papules,
nodules, and infiltration. Symmetrical nerve involvement with glove and stocking
sensory impairment.
Systemic involvement common:
 Lymphadenopathy.
 Hepatosplenomegaly.
 Ocular involvement.
 Testicular atrophy.

7. Indeterminate leprosy: ill-defined,
hypopigmented,
hypoesthetic lesion on the face; the lesion
is
always macule.
Tuberculoid leprosy: well-defined
hypopigmented,
hypoesthetic plaque. Note the feeder
nerve

8. Borderline tuberculoid leprosy:
A: welldefined,hypoesthetic,
erythematous plaque
Borderline lepromatous leprosy:
A: multiple plaques present almost
symmetrically

9. A: diffuse infiltration
of face.
B: infiltration of ear lobule.

11. nasal deformity
and supraciliary madarosis

12. lepromatous nodules on infiltrated
skin on chin.
histoid nodules on normal skin

14.  Cardinal signs
 According to WHO, in an endemic area, an individual should be regarded as
having leprosy if he or she shows ONE of the following cardinal signs:
 Skin lesion(s) consistent with leprosy with definite sensory loss, with or without
thickened nerves.
 Skin smears positive for acid fast bacilli.
 A person presenting with skin lesions or with symptoms suggestive of nerve
damage, in whom the cardinal signs are absent or doubtful, should be called a
‘suspect case’ in absence of an obvious alternate diagnosis..

15.  Such individuals should be counselled and advised to follow up if signs persist for
more than 6 months or if there is any worsening.
 Suspect cases may be also sent to referral clinics with more facilities for diagnosis

16.  Thickened peripheral nerves is typical.
Apart from larger nerve trunks, a feeder
nerve to the skin lesion may be
thickened.
 In distal extremities—glove and stocking
anesthesia (in BL, LL) and weakness of
muscles supplied by the affected nerve.

17.  Two types of reactions occur in leprosy—type 1 and type 2 reactions
 Type 1 lepra reaction:
 Occurs in borderline leprosy (the unstable varieties—BT, BB and BL).
Pathogenesis: Is due to alteration in the host’s CMI,
Manifestations: Characterized by:
 Erythema, edema, and scaling of the preexisting lesions
 Appearance of new lesions.
 Neuritis, clinically manifesting as nerve tenderness, and appearance of increasing new
areasof sensory impairment and motor deficits.

18.  Leprosy in type 1 reaction: erythema,
edema and scaling of pre-existing
lesions.

19.  Occurs most commonly in LL and sometimes in BL leprosy.
Pathogenesis: Immune complex reaction.
Manifestations: Characterized by:
 ENL: appearance of several tender, evanescent (quickly fading or
disappearing),erythematous nodules on face, flexures ,and legs; sometimes these
lesions may become pustular and ulcerate.
 Neuritis.
 Arthralgia, orchitis, and iridocyclitis.

20. evanescent,
tender, erythematous nodules.
necrotic ENL.

21.  Positive skin smears:Slit smear
 Smears are taken from skin lesions, ear lobules,eye brows, and sometimes dorsae
of fingers.on Zeihl–Neelsen staining, rod-shaped, red-stained leprosy bacilli may
be seen.
 Tests to confirm diagnosis of leprosy
 Biopsy:

22. Tests to evaluate systemic involvement:
 Hematological parameters:
 Anemia:
 Leucocytosis:
 Renal function tests
 Chest X-ray: Ruling out concomitant pulmonary tuberculosis is important

23. General measures:
 Reassuring patient.
 Education regarding low contagiousness.
 Advice regarding sensory impairment especially with regard to hands and feet.
 Care of hands, feet, and eyes.
 Counseling regarding regularity of treatment.

26.  • disfigurement
 • hair loss, particularly on the eyebrows and eyelashes
 • muscle weakness
 • permanent nerve damage in the arms and legs
 • inability to use the hands and feet
 • Nosebleeds
 • iritis (inflammation of the iris of the eye), glaucoma (an eye disease that causes
damage to the optic nerve), and blindness
 • Infertility
 • kidney failure