Role of Hormones in Pilosebaceous Unit Development

Abstract

Androgens are required for sexual hair and sebaceous gland development. However, pilosebaceous unit (PSU) growth and differentiation require the interaction of androgen with numerous other biological factors. The pattern of PSU responsiveness to androgen is determined in the embryo. Hair follicle growth involves close reciprocal epithelial-stromal interactions that recapitulate ontogeny; these interactions are necessary for optimal hair growth in culture. Peroxisome proliferator-activated receptors (PPARs) and retinoids have recently been found to specifically affect sebaceous cell growth and differentiation. Many other hormones such as GH, insulin-like growth factors, insulin, glucocorticoids, estrogen, and thyroid hormone play important roles in PSU growth and development. The biological and endocrinological basis of PSU development and the hormonal treatment of the PSU disorders hirsutism, acne vulgaris, and pattern alopecia are reviewed. Improved understanding of the multiplicity of factors involved in normal PSU growth and differentiation will be necessary to provide optimal treatment approaches for these disorders.

Milk consumption and acne in teenaged boys

“…29 Milk also contains estrogens, some of which are produced in the lactating bovine mammary gland and are direct suppressors of sebaceous gland function. 30 Milk intake may also affect comedogenicity through the IGF-I pathway, particularly the ability of IGF-I to increase levels of circulating androgens. In two large cross-sectional studies, milk consumption was positively associated with higher plasma IGF-I levels 31,32 and in both studies, this was predominantly an association with skim milk.…”

“…38 Although both serum androgens and IGF-I levels increase at puberty, the period of maximum prevalence of acne, the course of the condition follows the levels of IGF-I more closely than it does androgens. 30 Recent work has demonstrated the association of acne with the ingestion of a high glycemic load diet, with improvement occurring on a change to a higher protein, lower glycemic load diet. 4 The mechanism suggested for this relationship is through the induction of increased amounts of testosterone by elevated insulin and IGF-I levels secondary to dietary influences.…”

Polycystic Ovary Syndrome in Adolescence

“…Any of these hirsutism equivalents may be the only cutaneous sign of androgen excess. Female-pattern hair loss usually is configured differently than male-pattern baldness: it typically begins in the fronto-parietal area and is fairly diffuse [66].…”

“…Approximately one half of mildly hirsute women and one sixth of moderately hirsute women have idiopathic hirsutism, in the sense of having no biochemical evidence of hyperandrogenism [66]. Usage of this term is evolving, however.…”

“…1). Hirsutism is excessive sexual hair that appears in a male pattern [66]. It is commonly graded according to the Ferriman-Gallwey system, where a score of less than eight is normal in adults (Fig.…”