Diagno Sis and Mana Gement O F Single Lesions in Lep R O Sy

Most clinicians will probably agree that it is more difficult to ascertain the diagnosis leprosy if only one skin lesion is found (which looks like leprosy) than if the patient presents with several lesions. In other words, a high sensitivity (few false negative diagnoses) and a high specificity (few false positive diagnoses) are difficult to achieve in patients with only one skin lesion, and in particular, if the single lesion is on the face, where unimpaired sensation does not exclude a diagnosis of leprosy.' If the single lesion is an enlarged nerve many clinicians will 'for all practical purposes' decide that the diagnosis must be leprosy and that antileprosy treatment should be commenced although, even in highly endemic areas, not all nerve enlargement is due to leprosy. In Ethiopia definitive histopathological evidence of leprosy was found in only 42 out of 8 1 biopsies from (presumably enlarged) peripheral nerves .2 There have also been several reports about ischiatic nerve damage following injections of quinine, which can be confused with nerve damage due to primary neuritic leprosy.3,4