What term describes an abnormal excess of vellus-type hair, which may be darker than usual?

The term that describes an abnormal excess of vellus-type hair is hypertrichosis. This condition involves an increase in hair growth that can occur on any part of the body and is not necessarily related to an increase in androgens, which distinguishes it from other conditions.

Vellus hair is the fine, light body hair often referred to as "peach fuzz." When hypertrichosis occurs, this vellus hair can become darker and more pronounced, leading to a noticeable change in appearance. This can be a congenital condition, occurring from birth, or it can develop later in life due to various factors, including certain medications, hormonal changes, or skin disorders.

Understanding hypertrichosis is crucial in electrolysis, as it helps professionals differentiate between various hair types and conditions they may encounter in their practice. The other terms listed refer to different hair loss or growth conditions, and do not appropriately describe excessive vellus hair.