Final answer:
Leucotrichia is caused by the loss of hair color, often connected with conditions like vitiligo that damage pigment-producing cells in hair follicles.
Step-by-step explanation:
The cause of Leucotrichia in dermatological response to damage lesions is B) Loss of hair color. This condition is often associated with vitiligo or can be a result of severe damage to hair follicles, where pigment-producing cells are unable to repopulate the hair structure, leading to white hair growth. It is not caused by a fungal infection, increased blood flow, or an autoimmune disorder, which are related to other dermatological symptoms and diseases like increased redness of inflammation, vasculitis, and autoimmune diseases that affect hormone gland function like Addison's disease, Graves' disease, and Hashimoto thyroiditis.