Is seborrheic alopecia the same as androgenetic alopecia?
Jul 14, 2022
Source: Cainiu Health
Dr. Liu Wan
Introduction
Androgenetic alopecia and seborrheic alopecia refer to the same condition, though the differing terminology reflects varying interpretations of the disease. In the early stages of seborrheic alopecia, hair gradually thins while scalp oil (sebum) production increases markedly. Additionally, some individuals frequently develop seborrheic dermatitis concurrently. Excessive sebum secretion leads to follicular obstruction, impairing nutrient delivery to hair follicles and thereby causing hair loss.
Androgenetic alopecia is a term used in Western medicine, named based on the underlying cause of hair loss—primarily excessive secretion of androgens in the body, which continuously attack hair follicles, leading to hair loss. Concurrently, the scalp often becomes excessively oily. Are seborrheic alopecia and androgenetic alopecia the same condition?
Are seborrheic alopecia and androgenetic alopecia the same?
Androgenetic alopecia and seborrheic alopecia refer to the same condition, though the differing terminology reflects varying conceptual understandings of the disease. In early-stage seborrheic alopecia, hair gradually thins while scalp oil (sebum) production increases significantly. Additionally, some individuals frequently develop seborrheic dermatitis. Excess sebum can clog hair follicles, impairing nutrient delivery to the follicles and thereby contributing to hair loss.
However, modern medical research has demonstrated that hair loss is not directly caused by excess oil. The sebaceous glands—structures responsible for oil production—are distinct from hair follicles, where androgen-sensitive vellus hairs originate. Androgen sensitivity varies among individuals: when both hair follicles and sebaceous glands are sensitive to androgens, two distinct phenomena occur. In hair follicles, androgen sensitivity causes progressive miniaturization—from large terminal follicles to smaller ones, eventually transforming into vellus-like follicles and ultimately disappearing entirely.
As a result, hair transitions from thick and long to thin and short, and eventually ceases growing altogether. Meanwhile, if sebaceous glands are androgen-sensitive, they become hyperactive and produce increased sebum. Thus, excess oil and hair loss are not causally related but rather parallel manifestations of the same underlying pathophysiology. Therefore, seborrheic alopecia and androgenetic alopecia describe the same clinical entity. We hope this explanation proves helpful!
