Genetic Hair Loss in Women
Table of contents
- 1 Genetic Hair Loss in Women
- 1.1 Mechanism of Genetic Hair Loss in Women
- 1.2 Medical Conditions That Can Cause Diffuse Hair Loss in Women
- 1.3 Drugs That Can Cause Diffuse Hair Loss in Women
- 1.4 Causes of Telogen Effluvium
- 1.5 Causes of Anagen Effluvium
- 1.6 Localized Hair Loss
- 1.7 Non-Scarring Alopecias
- 1.8 Scarring Alopecias
- 1.9 Hair Loss in Women and Aging
Female pattern hair loss is mostly associated to genetically inherited hair loss tendency. In some of the female pattern hair loss (FPHL), DHT is not always the culprit. In most cases hormonal irregularities and hyperandrgenic abnormalities also leads to female pattern baldness. FPHL is the most common cause of hair loss in women and its prevalence keeps rising with age. In Female pattern hair loss (FPHL), there is diffuse hair loss or thinning over the scalp due to advanced hair shedding or decrease in hair volume, or both.
Another hair loss condition in women referred to as chronic telogen effivium also introduces with increased hair shedding and is often perplexed with FPHL. It is very essential to clearly distinguish between these conditions as tackling with for both conditions differ.
In some cases the diagnosis can be made clinically and the disorder is treated pharmacologically. While many women using oral topical minoxidil and antiandrogens will regrow some hair, early identification and treatment is preferable as these treatments are works well at arresting progression of hair loss than triggering hair re-growth.
Correspondingly non-medical treatment techniques such as cosmetic camouflaging, hair transplantation and counseling are significant measures for some patients. The histology of female pattern hair loss implies the condition to be chronically progressive. So, all treatments are recommended to be continued to maintain the effect. A therapeutic process takes 12 to 24 months for potential response. Affected women may encounter impaired psychological anxiety and crippled social functioning.
It is very rare for women to bald following the male pattern baldness (which generally initiates with a receding frontal hairline that advances to a bald patch on top of the head) unless there is outrageous formation of androgens in the body.
Mechanism of Genetic Hair Loss in Women
Common form of baldness in females, also known as female pattern alopecia, has a sound genetic predisposition. Female genetic hair loss crucially emanates from a complicated stew of genes, aging, hormones and even many more players. The mode of inheritance is polygenic, demonstrating that there are good numbers of genes that leads to FPHL, and these inherited genes could be obtained from either parent, or both. Testing for hereditary hair loss from mother or father to ascertain the risk of balding is presently not recommended, as it is not a reliable option.
Many research studies exhibits that the initial functioning of pilosebaceous units of hair follicles amongst women starts in utero. The physiology is fundamentally androgenic, with DHT (Dihydrotestosterone) the major contributor at dermal papillae.
In summation to 5-a reductase, dihydrotestosterone (DHT) and testosterone; which are also prevalent in men’s hair loss; also exits in females are the enzyme aromatase and the female hormones estradiol and estrone. So let’s understand the process that contributes to common hair loss in women.
In both males and females, 5-a reductase responds with testosterone to yield DHT, the hormone which play a key role for the miniaturization (diminishing) and steady suspension of affected hair follicles. This extensively describes why both women and men lose their hair. But one of the rationales why women scarcely have the apparent bald areas that men do is because women customarily have only half the amount of 5-a reductase as compared to men.
Adding to this problem, in females, the enzyme aromatase is the major contributor of the production of the female hormones, i.e., estrone and estradiol, counteract the action of DHT. Women naturally have higher amount of aromatase than men, particularly at the frontal hairline. It is this existence of aromatase which may aid in understanding why hair loss in women looks so distinctive than in men, especially with regards to the conservation of the frontal hairline. It may also help to interpret why females have a bad response to finasteride (Propecia), a medication most widely used to treat hair loss in men that function effectively by impeding the formation of DHT.
Presently, it had been very vague if male sex hormones (androgens) literally contribute to FPHL, although androgens are assumed to play a clear role in male pattern baldness. The majority of females with FPHL have normal to average levels of androgens in their bloodstream. Due to this undetermined correlation, the term FPHL is referred to ‘female androgenetic alopecia’.
Medical Conditions That Can Cause Diffuse Hair Loss in Women
Women’s hair and follicles appears to be specifically sensitive to suppressed medical conditions. Since intrinsic medical conditions commonly cause a diffuse type of hair loss pattern that can be confused with genetic balding, it is essentially required that women with undiagnosed alopecia be appropriately examined by a physician specialized in hair loss.
Check here for the systemic medical conditions that causes diffuse pattern of hair loss:
- Gynecologic and child-birth conditions; such as post-menopausal states and ovarian tumors
- Both hyperthyroidism and hypothyroidism leads to diffuse telogen hair loss.
- Chronic disorders like inflammatory bowel disease, systemic amyloidosis, lymphoproliferative disorders, chronic renal failure and hepatic failure results in telogen hair shedding.
- Autoimmune diseases such as dermatomyositis, systemic lupus and erythematosus
- Inflammatory disorders such as seborrheic dermatitis, psoriasis, and allergic contact dermatitis
- Chronic infections such as secondary syphilis and human immunodeficiency virus
- Anemia (iron deficiency)
- Lupus- a Connective tissue disease
- Nutritional deficiency, zinc deficiency, low protein/calorie count, essential fatty acid, malabsorbtion, crash dieting and hypervitaminosis
- Distress from clinical procedures, anesthesia, or emotional issues
Drugs That Can Cause Diffuse Hair Loss in Women
Among the many known causes of hair loss in women, drug-induced hair loss is one of the most disregarded causes. FPHL from drugs is a generally reversible diffuse non-scarring hair loss that happens within days to a month of beginning a new medication or changing the dose. It may be stressful for the patient and may also result in to poor compliance with the treatment.
Anagen effluvium is most widely recognized after intake of cytotoxic drugs. Drug-induced hair shedding is awful and severe and may contribute to loss of large amount of the scalp hair, eyelashes and eyebrows.
Telogen effluvium is the commonest type of hair loss prompted by drugs and is presented with abnormal shedding of telogen hairs. Drugs are known to promote effluvium through 3 distinct mechanisms i.e.:
- By accelerating the hair follicle into premature rest.
- As a repercussion of discontinuation of drugs that extends the time duration of anagen for example, oral contraceptives and topical minoxidil.
- Premature separation of the club hair from the hair follicles with compressing of the normal telogen phase, for example, retinoids.
Causes of Telogen Effluvium
- Anti-coagulants such as warfarin, heparin and prospectively the newer anticoagulants like apixaban, rivaroxaban and dabigatran
- Anti-hypertensives such as ACE inhibitors and beta-blockers
- Oral contraceptive pills(specifically those high in progestins), androgens and hormone replacement therapy
- anticonvulsants such as carbamazepine up to 6%, phenytoin, valproic acid 12-28% (dose-dependent)
- Antidepressants, e.g. lithium 12-19% and Mood stabilizers
- antipsychotic and anti-anxiety drugs such as amitriptyline
- Anti-inflammatory such as levodopa, bromocriptine,
- anti-infective agents, amphetamines,
- cholesterol lowering drugs, interferons
- Anti-thyroid drugs, nonsreoidal
- Others such as –retinoid, isotretinoin, cimetidine, acitretin.
Telogen effluvium may also take place as a consequence of a severe drug eruption such as toxic epidermal necrolysis, drug hypersensitivity syndrome, Stevens Johnson syndrome in which hair shed for few weeks to month after serious sickness and gradually re-grows again.
Causes of Anagen Effluvium
- Chemotherapy drugs
- Poisining with thallium, arsenic or bismuth
- Boric acid
- Rarely with Colchicine
Localized Hair Loss
Scores of dermatologic conditions contribute towards localized hair loss in women and the pattern that they form is generally pretty different from the diffuse pattern hair loss in women. A female genetic hair loss and localized hair loss is easily distinguished by a skilled dermatologist. However sometimes, the diagnosis of localized hair loss is difficult to make and tests, such as a scalp biopsy are demanded.
LHL in women can be further sub-divided into non-scarring and scarring types.
Alopecia Areata is a genetically inherited, auto-immune hair disorder that exemplifies the non-scarring form. It presents with the unexpected onset of discrete, disc-shaped patches of hair loss linked with normal underlying skin. It is highly responsive to local injections of cortico-steroids.
Localized hair loss could also be a result constant pulling of scalp hair, either through using hair pieces, braiding, tight clips or tightly pulled back hair styles. The medical term used for this condition is called as Traction alopecia, that often leads to reversible thinning by simply keeping the hair loose but, if there is continuous strain on the hair follicles for an extended time period, the hair loss can become permanent.
Scarring hair loss can be caused by hosts of dermatologic or medical or conditions including local radiation therapy, Discoid Lupus, thermal burns, Lichen Planus and infections. Face-lift surgery can cause permanent localized hair loss that could be especially worrisome if it appears around the temples or at the frontal hairline. Luckily, localized hair loss from medical illness or any injuries are many times amenable to hair restoration.
Hair Loss in Women and Aging
Many of the stimulating elements that cause the rate of hair loss to accelerate or slow decelerate are not known, but what is known is that with age, a person’s total hair density will reduce. This is called as senile alopecia. Even when there is no predisposition to hereditary hair loss or balding, hair throughout the scalp will thin over time resulting in lower hair volume. The age at which these effects become obvious varies from one person to another and is mainly related to an individual’s genetic formation.