Final answer:
Eruptive dermatofibromas are associated with systemic conditions such as lupus and autoimmune diseases like type 1 diabetes mellitus. They can also be associated with malignancies, although this is less common. Lymphadenitis is the condition that typically results in the formation of a bubo.
Step-by-step explanation:
Eruptive dermatofibromas are associated with systemic conditions that typically involve immune dysregulation or chronic inflammation. While lupus (systemic lupus erythematosus) is a common cause of eruptive dermatofibromas, diabetes, specifically type 1 diabetes mellitus, which is an autoimmune disease, is also known to be associated with this skin condition. Additionally, malignancies can lead to paraneoplastic dermatoses, including eruptive dermatofibromas. However, the exact association with malignancies can vary and is less commonly reported than autoimmune conditions.
Regarding the conditions that result in the formation of a bubo, such as encountered in bubonic plague, lymphadenitis (option B) is the correct answer. Lymphadenitis refers to the inflammation of the lymph nodes, which leads to the characteristic swollen nodules known as buboes.
It is important to note that eruptive dermatofibromas represent a cutaneous manifestation which may point to a more systemic underlying issue, thus prompting further medical investigation to determine the presence of any associated conditions.