What skin manifestation is typically seen in leprosy caused by Mycobacterium leprae?

In leprosy, caused by Mycobacterium leprae, the skin manifestation typically observed is hypopigmented plaques. This characteristic change results from the pathogenic effects of the bacterium on the skin and peripheral nerves. Specifically, the loss of sensation due to nerve damage can lead to a reduction of melanin production in affected areas, leading to lighter (hypopigmented) patches of skin. These plaques often have a well-defined border and may not exhibit other symptoms like scaling or crusting.

While other skin lesions are observable in different conditions, in the case of leprosy, the presence of hypopigmented plaques is a hallmark feature that aids in its diagnosis, especially when accompanied by sensory loss in the areas affected. This synergy between skin findings and neurological impairment is key to identifying leprosy in a clinical setting.