Alopecia syphilitica is caused by which of the following conditions?

Alopecia syphilitica specifically refers to hair loss that occurs as a result of syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum. This condition can lead to various manifestations in the body, including hair loss. The presence of syphilis can result in systemic effects that affect the hair follicles, leading to conditions like alopecia.

When considering the other options, genetics, allergies, and stress can certainly contribute to hair loss in different forms (like androgenetic alopecia, alopecia areata, or telogen effluvium), but they do not directly cause alopecia syphilitica. The hair loss associated with those conditions is due to different underlying mechanisms than those caused by a syphilis infection, highlighting the importance of understanding the specific causative factors in different types of alopecia.