Hair Growth – Understanding a Complex Process

Hair loss is a major problem for men and women in the United States. It is estimated that 35 million individuals suffer from hair loss that affects their sense of well being and ability to socialize or work in a more productive manner. This is an explanation of what is involved in the detailed process of hair growth.

There are few sites in the body that contain stem cells. Stem cells are undifferentiated cells that can transform into various tissue, depending on what tissue needs to be regenerated. In addition to bone marrow, the hair follicle is one of the only place in the body that stem cells are found. These hair follicle stem cells are located at the base of the hair root know as the bulge. When activated, these stem cells migrate to the hair follicle papillary area which is at the very base of the hair shaft. These stem cells then interact with the hair dermal matrix papillary tissues to begin to grow new hair. This complex interaction is mediated by growth factors and cytokines. Cytokines are cell-signaling proteins that are secreted by cells and are contained in platelet rich plasma. They are the signaling molecules that are involved in cell to cell communication. When activated, the hair follicle stem cells and dermal papilla cells release cytokines. PRP enhances and stimulates release of these cytokines.

The cells of the hair root are highly specialized for rapid growth and division. Given the right signaling, these cells produce actual hair and the pigment that give hair its color. The dermal papilla is in direct contact with the cells of the hair matrix. It is the dermal papilla that plays the major role in controlling hair growth. It is the complex interaction of the activated stem cells, hair matrix and dermal papilla that ultimately results in new hair production.

Hair growth is divided into 3 stages: anagen, catagen and telogen. Ninety percent of human hair is in anagen stage, which is the active growth stage. Anagen phase can last 2-6 years. Anagen phase is controlled by numerous factors. Androgens (e.g. testosterone) has a direct effect on anagen phase. After the anagen phase, hair enters the catagen phase which is short in duration, usually 2-3 weeks. During this time, the hair matrix stops producing hair and keratinizes (forms into solid protein.) This phase is then followed by telogen phase where the hair shaft falls out. Telogen lasts anywhere from 3-4 months. If the hair follicle is still active, a new hair matrix will form from the stem cells in the bulge area. New hair growth begins and this starts the anagen phase again. In androgenic hair loss (male pattern baldness, MBP) hair follicles end up staying in the telogen phase and no new hair growth occurs. This is under the influence of another androgen, dihydrotestosterone (DHT), which is a transformed version of testosterone. The conversion of testosterone to DHT is controlled by an enzyme, 5-alpha reductase. Medications are available to dramatically stop production of DHT and thereby slow down or stop the loss of hair.

Tags: , , , , , , , , ,

About Dan Kassicieh, D.O.

Dr. Kassicieh is a Board-Certified Neurologist and is the medical director of the Florida Headache and Movement Disorder Center. He has been practicing in Sarasota for over 23 years. Dr. Kassicieh is a Fellow of the American Academy of Neurology and the American College of Neuro-psychiatrists. Both of these honors were awarded to him on the basis of his extensive research experience, medical publications and continued support of patients and their families who are affected with neurological disorders. Dr. Kassicieh is a sought-after public speaker and is frequently a presenter both within the medical community and in the public forum. He has appeared regularly on local television and is considered an expert in a number of areas within his specialty. Dr. Kassicieh’s primary medical interests are in the treatment of headache, neck and back pain. He specializes in non-surgical neuro-orthopedics. The goal in treatment of patients is to restore them to a pain free status without the use of narcotics or surgery. To this end, he has had training in Platelet Rich Plasma therapy. From his successes with this for neuro-orthopedic problems, it was only natural that he use platelet rich plasma to help patients with hair loss. Giving each patient the best quality of life is our goal at Sarasota Neurology.

Comments are closed.