With special thanks to Jeannette Johnson for her kind advice and attention.
Hair roots contain sebum. Sebum contains fatty acids and tryglycerides, and plays a role in some crucial body functions, such as hydration, inflammation, antioxidants, antimicrobial lipids, and pheromones. Sebum levels increase during puberty and excessive levels of sebum are often associated with skin problems, making it relevant to skin picking and hair pulling.
Why is this so relevant? You probably know that the body’s energy levels revolve around its production and use of insulin. a hormone which regulates fat and carbohydrate metabolism. It is insulin which prompts cells to absorb glucose from the blood. In fat cells, glucose it is stored as triglycerides .. see above paragraph for relevance of tryglycerides.
A normal skin yeast, Malassezia, may be overgrown in people with trichotillomania and dermatillomania. Overgrowth of malassezia is linked to higher levels of oleic acid in the sebum, which we think is caused by a delta 6 desaturase deficiency. According to Wikipedia, Malassezia is related to most skin disease in humans, certainly to eczema and acne. Malassezia growth depends upon the presence of fats, and sebum, which you will recall is present in hair roots.