Which condition is characterized by febrile, rapidly progressing skin lesions, starting as painless macules and developing into necrotic, gangrenous ulcers?

The condition characterized by febrile, rapidly progressing skin lesions that start as painless macules and develop into necrotic, gangrenous ulcers is indeed ecthyma gangrenosum. This condition is often associated with infections caused by Pseudomonas aeruginosa, particularly in immunocompromised patients or those with underlying health issues. The initial skin lesions appear as flat, red papules or macules, which rapidly change to vesicular lesions and eventually ulcerate, leading to areas of necrosis and eschar formation.

The progression of the lesions from macules to necrotic ulcers occurs quickly, often accompanied by systemic symptoms such as fever, indicating a severe infection. Importantly, ecthyma gangrenosum is distinguished from other skin infections by its association with Pseudomonas and its potential to occur in individuals with severe underlying conditions, such as neutropenia or cancer.

The other conditions, while they may involve skin lesions or infections, do not typically present with the same pattern or rapid progression seen in ecthyma gangrenosum. For instance, impetigo is generally superficial, characterized by honey-colored crusts and is not prominently associated with necrosis. Necrotizing fasciitis involves deeper tissue