Leprosy is a chronic infectious disease caused by the acid-fast bacillus Mycobacterium leprae. It is transmitted through inhalation of droplets or direct skin contact with an infected person. The incubation period ranges from 3 to 5 years. Leprosy presentations range from tuberculoid leprosy with localized lesions and strong immune response to lepromatous leprosy with numerous skin nodules and a weak immune response. Diagnosis involves examining skin and nerve lesions for acid-fast bacilli and performing a skin biopsy. Treatment consists of multidrug therapy with dapsone, rifampicin, and clofazimine for a duration dependent on leprosy type and

1. Leprosy Definition: It is a chronic infectious systemic disease of man caused by mycobacterium leprae. Etiology: Caused by : Mycobacterium leprae -Acid fast bacilli. -Obligate intracellular organism. -Not grow on artificial culture media.

2. Mode of transmission: 1.Air-borne transmission: through inhalation of the bacilli. 2.Indirect transmission: Clothes and sleeping mates . 3.Direct contact with skin.

3. Incubation period : 3-5 years . Classification of Leprosy : 1.Indeterminate leprosy. 2.Tuberculoid leprosy . 3.Border-line leprosy: i.Borderlinetuberculoid. ii.Borderline borderline. iii.Borderlinelepromatous. 4.Lepromatous leprosy

4. Clinical Picture : Indeterminate Leprosy : -Non-specific hypopigmented ill-defined macule having normal sensation. -Affecting mainly the face,extrmities or the trunk. Fate of indeterminate leprosy is disappearing or changing to tuberculoid or lepromatous leprosy.

5. Borderline Leprosy : Manifestation are in between the tuberculoidand lepromatous leprosy. If these are more towards tuberculoid = bordeerlinetuberculoid. If these are more towards lepromatous= borderline lepromatous.

7. Complication of leprosy: 1.Muscle paralysis. 2.Trophic ulcer. 3.Testicular atrophy. 4.Amyloidosis. 5.Blindness. 6.Charcot joints.

8. Diagnosis: 1.History. 2.Symptoms and signs. 3.Bacteriological examination of smear from specific lesion=acid fast bacilli. 4.Skin biopsy. N.B: lepromin test is not diagnostic test but it determines theimmunological state of the patient to help in classifying the disease(tuberculoid or lepromatous).

9. Treatment: 1.Multiple drug therapy: i.Dapsone. ii.Rifampicin. Iii.Clofazimine. Duration of treatment depend on : A.type of leprosy. B.Disappearance of lepra bacilli from the skin smear. 2.treatment of complications.