How can granuloma inguinale progress from a small sore to a destructive ulcer?

Granuloma inguinale is a sexually transmitted disease caused by the bacterium Calymmatobacterium granulomatis (also known as Klebsiella granulomatis).123

The pathology of the disease typically begins with the appearance of painless papules on the genitals, thighs, or groin. As the infection progresses, these initial papules become ulcerated. Over time, these lesions develop into granulomatous masses—tissue characterized by the formation of granulations—that are prone to bleeding easily. If left untreated, these deep, purulent ulcers can become highly destructive to the affected areas.231

Because these lesions can mimic other conditions like syphilis, clinical diagnosis often involves identifying Donovan bodies within biopsy material or lesion smears. The condition is effectively managed with [antibiotics].12