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Hansen’s Disease (Leprosy)

»	What causes leprosy?
»	Why is leprosy called Hansen’s disease?
»	How is leprosy transmitted?
»	Are children and adults equally susceptible to acquiring leprosy?
»	Are humans the only host for M. leprae?
»	Is leprosy a systemic disease?
»	How common is leprosy?
»	Are there endemic areas for leprosy in the United States?
»	How is leprosy recognized clinically?
»	Is there more than one kind of leprosy?
»	Does indeterminate leprosy mean that you do not know what type it is?
»	What are the two “polar” forms of leprosy? How do they differ?
»	Describe dimorphous leprosy.
»	What is the unusual feature of the cell-mediated immunity in lepromatous leprosy?
»	Define the cytokine response to M. leprae in tuberculoid versus lepromatous patients.
»	How is the diagnosis of leprosy usually made?
»	What area should be biopsied to detect M. leprae?
»	Can the same acid-fast stain used for Mycobacterium tuberculosis be used for the leprosy bacillus?
»	What are Virchow cells?
»	Is the lepromin skin test helpful in making a diagnosis of leprosy?
»	Is the neuropathy in lepromatous leprosy the same as that in diabetic neuropathy?
»	Describe a patient with advanced lepromatous leprosy.
»	What are the most common complications in leprosy?
»	What are the reactional states of leprosy?
»	What drugs are used in multidrug therapy for leprosy?
»	Do the recommendations of the World Health Organization (WHO) differ from those of the U.S.?
»	What are the side effects of the drugs for leprosy treatment?
»	What is the most bothersome cutaneous side effect of clofazimine?
»	How are the reactional states of leprosy treated?
»	Should family members of leprosy patients be treated?
»	Can leprosy be eliminated as a worldwide disease, as smallpox has been?

Is there more than one kind of leprosy?

Skin lesions in four variants of leprosy. A, Indeterminate leprosy. A solitary erythematous macule on the face of a young family member of a patient with lepromatous leprosy. B, Tuberculoid leprosy. A solitary, well-circumscribed, annular anesthetic patch on the leg. C, Dimorphous leprosy. A solitary anesthetic annular patch with a scaly border on the trunk. D, Lepromatous leprosy. Coalescent brown, firm nodules on an extremity.

Fig. 29.1 Skin lesions in four variants of leprosy. A, Indeterminate leprosy. A solitary erythematous macule on the face of a young family member of a patient with lepromatous leprosy. B, Tuberculoid leprosy. A solitary, well-circumscribed, annular anesthetic patch on the leg. C, Dimorphous leprosy. A solitary anesthetic annular patch with a scaly border on the trunk. D, Lepromatous leprosy. Coalescent brown, firm nodules on an extremity.

Four major variants of leprosy represent a spectrum of disease: indeterminate leprosy, tuberculoid leprosy, lepromatous leprosy, and dimorphous (or borderline) leprosy (Fig. 29-1). The lepromatous form is seen twice as frequently in men as in women. Although it varies from country to country, about 90% of the leprosy cases in the United States are of the lepromatous type.