Demystifying Hair Loss: What is Alopecia?

Alopecia or hair loss is a worldwide problem affecting both gender. Usually people have around 100000-150000 hair on head. Each hair undergo several changes starting from growth phase till shedding. The hair growth cycle is broadly divided into 3 phases. The anagen stage refers to the growth phase which lasts for 2-5 years. The catagen phase runs for couple of weeks where the hair prepares itself for telogen phase. The telogen or resting or shedding phase which may runs for 3-4 months is the stage where hair will fall out and new hair will grow. Approximately 100 hair fall/day is considered to be normal but in case it increases to significant level then it is referred as alopecia or hair loss.

Usually at any given point of time approximately 85-90% hair are in anagen stage while rest 10-15% can be in catagen or telogen stage. In the conditions where this ratio is disrupted, the pareson will experience more hair loss. Genetics, hormones, drugs, environment, stress, immunity, diet, diseases, etc. can influence hair growth and anagen to telogen ratio of hair follicles.

Alopecia can be of different types. Androgenetic alopecia has genetic factor and is hereditary in nature. It is further divided into male pattern baldness (MPB) or female pattern baldness (FPB) depending upon gender affected. Alopecia areata affects almost 2% of population and presents as round patches on scalp or hair bearing areas. Chronic telogen effluvium is another condition which can affect A:T ratio and increased hair loss without any cause. Scarring alopecia is a very serious situation where the scalp appears bald and scarred (similar to oil burns). Other types of hair losses are alopecia universalis or totalis.

Androgenetic Alopecia (AGA)

Androgenetic Alopecia (AGA) is a common type affecting both genders. The patients suffering from androgenetic alopecia can reveal hereditary or positive family history and pattern hair loss. It can be divided into male or female pattern AGA. The role of testesterone, DHT & androgen hormones (sex hormones) has been seen in males leading to AGA. In females the exact mechanism of hair loss is unclear & hormones, genetic variations and other factors have been considered causing female pattern baldness. The AR gene & ectodysplasin A2 receptor EDA2R have shown to send strong signals to androgenetic alopecia.

Male Pattern Baldness

Male pattern baldness is an androgentic alopecia affecting almost more than 10 million males only in India. It can be found in approximately 50% of males below age of 40 and almost every men at older age of life. Positive family history and hormonal influence is well documented with male pattern hair loss. It mainly occurs due to the effects of dihydrotestosterone (DHT) in front and crown region of scalp. The 5-alpha reductase enzyme is responsible for conversion of circulating testosterone into 5-alpha dihydrotestesterone. DHT mainly influences hair growth cycle and causes shortening of anagen phase leading to miniaturization or thinning of hair follicles, reduction in hair follicles per graft or scalp and ultimately baldness. The terminal hair (thicker hair) are converted into vellus hair (thin “baby” hair). The male pattern baldness presents as hair thinning, receding hairline, loss of hair from front and centre of head (vertex and crown) but hair from both the sides and back region of scalp is spared.

The researchers have studied pathology of androgenic alopecia and have putforth various explanations for development and progression of AGA. The activity of androgenic hormones and genetic factors lead to microinflammation, progressive fibrosis of perifollicular area, changes in cell interaction & Wnt signals, changes in hair stem cells and muscles. All these microscopic changes can cause hair thinning or miniaturization.
The biopsy of follicular unit or scalp can show increase in size of oil secreting sebaceous glands, dermal thinning and perifollicular macrophage infiltration and inversion of A:T ratio (anagen to telogen ratio), increase in number of vellus hair. These features correlates with the facts that the patients suffering from AGA also complaints of decreased hair growth, mini-hair in the affected area and oily scalp along with hair fall.

There are scientific classifications of the severity and stages of androgenetic alopecia for both males and females. The Hamilton-Norwood classification is widely used classification for male pattern baldness.

The enzyme called 5-alpha reductase chiefly controls production of DHT and hence the medical approaches are focussed on targeting this enzyme and DHT hormone. Currently Minoxidil, Finasteride, Dutasteride, saw palmetto, etc. are known to reduce male pattern baldness. Mesotherapy, platelet rich plasma (PRP), dermaroller helps in controlling hair loss while hair transplant can be done to cover bald area or treat baldness.

Female Pattern Baldness (FPHL)

Female pattern hair loss (FPHL) is a preferred term over female androgenetic alopecia due to lack of confirmed correlation between androgen hormones. FPHL is the most common cause of hair loss in females. Female hair loss affects approximately 12% of young and 50% of older age group females (after menopause). Unlike males the females presents as hair thinning or hair loss in mid front area leaving hairline intact in most cases. Usually, the hairline is not disturbed, hair loss or hair thinning starts from mid partition area (center line of head) slowly covering entire scalp. The appearance sometimes is observed as Christmas tree.

As said earlier, unlike males the role of androgen hormones in female pattern baldness is questionable but the genetic causes have been considered as one of the factors. Several time females suffering from hair loss may also complaints of irregular periods or menstrual cycle, stress, nutritional deficiency, anemia, polycystic ovarian syndrome, thyroid, etc. In the end the male and female pattern baldness share common pathway leading to hair thinning, hairfall and baldness.

The Ludwig scale is commonly used classification system for FPHL. Scalp biopsy, hair pull test and trichoscan which is routinely done at our centre are the best tests to assess alopecia. Blood test can help in checking hormonal levels and nutritional status. At present only Minoxidil is approved by FDA for treatment of female pattern baldness. Use of hair wig, patches, fibers, weaving or hair transplant can be good options for bald areas.

There are more than hundred reasons for development of AGA. As per our research the development and progression of androgenetic alopecia depend on combination of several factors and not because of one single reason. Deficiencies of iron, zinc, biotin, vitamins, stress, pollution, etc. have been considered to be contributory factor in male pattern or female pattern baldness. Hence the diagnosis & treatment planning of AGA has to be focussed on addressing all of above factors rather than simply focussing on DHT.

Alopecia Areata

Alopecia areata appears as patchy hair loss. It affects almost more than 1 million Indians or 2% population worldwide. Alopecia areata is considered to be an autoimmune disorder where our own immunity responds against our own body cells considering them to be harmful. This response usually starts without any known reason but hormonal imbalance, stress are known factors.

Scalp biopsy and clinical examination can help in diagnosing alopecia areata. The patches appears round or oval with well defined margins in forhead or beard or hair bearing areas. The area can be itchy and very rarely painful. The alopecia areata should be differentiated with scarring alopecia as latter is much more difficult to treat.

Steroids injections or oral steroids are established treatment of alopecia areata. We have found more favourable results with combination therapy and our advanced hair boost therapy in regenerating hair at faster rate in areata.