Hansen's Disease / Leprosy (Mycobacterium leprae)
2013 Case Definition

Clinical Criteria

A chronic bacterial disease characterized by the involvement primarily of skin as well as peripheral nerves and the mucosa of the upper airway. Clinical forms of Hansen"s disease represent a spectrum reflecting the cellular immune response to Mycobacterium leprae. The following characteristics are typical of the major forms of the disease, though these classifications are assigned after a case has been laboratory confirmed.

• Tuberculoid: one or a few well-demarcated, hypopigmented, and hypoesthetic or anesthetic skin lesions, frequently with active, spreading edges and a clearing center; peripheral nerve swelling or thickening also may occur
• Lepromatous: a number of erythematous papules and nodules or an infiltration of the face, hands, and feet with lesions in a bilateral and symmetrical distribution that progress to thickening of the skin, possibly with reduced sensation.
• Borderline (dimorphous): skin lesions characteristic of both the tuberculoid and lepromatous forms
• Indeterminate: early lesions, usually hypopigmented macules, without developed tuberculoid or lepromatous features but with definite identification of acid-fast bacilli in Fite stained sections

Laboratory Criteria For Diagnosis

Confirmed:

• Demonstration of acid fast bacilli in skin or dermal nerve from a biopsy of a skin lesion using Fite stain, without growth of mycobacteria on conventional media (if done)

OR

• Identification of noncaseating granulomas with peripheral nerve involvement, without growth of mycobacteria on conventional media (if done)

Confirmed

A clinically compatible illness with confirmatory laboratory results.

• Hansen's Disease / Leprosy (Mycobacterium leprae) | 1997 Case Definition