Significance of nail changes in leprosy: a clinical review of 357 cases.

Leprosy can cause many nail changes, which have been observed in up to 64% of infected patients. The manifestations of leprosy (clinical, bacteriologic, and histological) are profoundly affected by the patient's immunological status, which also determines the prognosis. Nail changes in leprosy can be caused by neuropathy and trauma, vascular impairment, infections, and miscellaneous changes. Often more than one factor will be important. Paradoxically, nail changes in tuberculoid and lepromatous patients are similar, despite wide differences in pathology. This may be because etiological factors common to both are implicated. Factors only associated with lepromatous disease are invasion of the bones of terminal phalanges by lepromatous granulomas and endarteritis occurring during type 2 lepra reactions. Otherwise, the only difference from tuberculoid leprosy is the time of onset and the symmetry of lesions. Lepromatous patients develop nail changes late in the course of disease. The presentation is usually bilaterally symmetrical. However, these changes are not specific to leprosy, and may be observed in other peripheral neuropathies.