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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?

What are the two “polar” forms of leprosy? How do they differ?

Tuberculoid leprosy and lepromatous leprosy are considered the two polar forms, and they tend to remain stable clinically. Patients with tuberculoid leprosy have a high degree of immunity against M. leprae and have few skin lesions and few organisms in their skin. Patients with lepromatous leprosy have low immunity against M. leprae and have many skin lesions and millions of organisms in their skin (Table 29-1).

Table 29-1. Clinical Features of Leprosy Skin Lesions
	CUTANEOUS LESIONS	TUBERCULOID	DIMORPHOUS	LEPROMATOUS
	Number	Few	Many	Numerous
	Size	Large	Large and small	Small
	Symmetry	Asymmetrical	Symmetrical	Symmetrical
	Sensation	Anesthetic	Variable	Variable
	Surface	Rough, scaly	Rough, scaly	Smooth
	Edge	Sharp	Sharp	Vague