Overview of alopecia
Alopecia or hair loss is a common and distressing problem both in men and women of any age, particularly when it affects the scalp. The dilemma of lost scalp hair has been well documented throughout the history of modern man. Hair loss can range from a small bare patch to a more diffuse and obvious pattern. Androgenetic alopecia (AGA) is the most common cause of hair loss in women. Although medically benign, alopecia has been shown to have notably deleterious effects on body image, self-esteem and psychologic well-being.1
Although most alopecia is a concern for cosmetic and psychologic reasons, it can occasionally be the initial sign of an important systemic disease.2 A systematic approach to the patient with alopecia will enable clinicians to diagnose the problem accurately in majority of cases. The diagnosis is based on a detailed history, physical examination and in some cases, relevant laboratory tests along with scalp biopsy.
Depending on patient’s age, etiology and distribution of the alopecia, there are different medical and surgical treatment modalities. However, treatment is not mandatory as the condition is benign and spontaneous remissions and recurrences are common. Treatment aims at the regrowth of hair in affected individuals. The available therapeutic modalities may be used alone or in combination and may be individualized to meet the specific needs of the patient.
Evolutionary Trend of Alopecia
Baldness is not specifically a human trait. The human being has evolved to become a naked monkey. Some primates such as chimpanzees and stump-tailed macaques show progressive thinning of the hair on the scalp after adolescence. A number of other primate species also experience hair loss following puberty, and some primate species had been observed to use an enlarged forehead, created either anatomically and/or through strategies such as frontal balding, to convey an increase in the status and maturity.
The development of a scientific understanding of the evolution of human hair diversity is hindered by the insufficiency of fossil and archeological records of hair. It has been suggested that scalp hair evolved in order to protect the scalp from the harmful effects of the sunlight and to conserve body heat. One theory suggests baldness evolved in males through sexual selection as an improved sign of aging and social maturity, increase in nurturing habits and decrease in aggression and risk-taking behaviors. The Egyptians were the first civilization that dedicated special care to their hair.
Normal Hair Growth
Hair is an important emblem of health, youth and vitality. Each day the scalp hair grows approximately 0.35 mm. The scalp sheds approximately 100 hairs per day. Each hair follicle passes through 3 phases of growth cycle as the following:
- Anagen or growth phase on the scalp lasts for an average of 3 years. The duration of the anagen phase varies from person to person and it determines how long hair will grow if not cut. At any one time, approximately 85 to 90 percent of scalp follicles are in the anagen phase of growth.
- Catagen phase follows the anagen and is an involutional stage that lasts around 2 weeks. It affects 2 to 3 percent of hair follicles.
- Telogen or dormant phase lasts about 3 months. About 10 to 15 percent of hair follicles undergo a rest period and does not grow. At the end of this phase, the inactive or dead hair is ejected from the skin, leaving a solid, white nodule at its proximal shaft. The cycle is then repeated.
The length of each phase of the cycle and that of the entire cycle, varies with the site and the age of the patient.
Types of Alopecia
Most hair loss can be categorized into three types:
- Noncicatricial (potentially reversible).
- Cicatricial (irreversible hair loss associated with destruction of the stem cell reservoir).
- Hair loss due to hair shaft abnormalities.
Noncicatricial alopecia has several subtypes:
- Androgenetic alopecia (common baldness).
- Alopecia areata (isolated or recurrent patchy hair loss).
- Traction alopecia and trichotillomania.
- Telogen effluvium (shedding).
- Anagen effluvium.
The cicatricial alopecia refers to a diverse group of rare disorders that destroy the hair follicle, replace it with scar tissue and cause permanent hair loss. Common causes are fungal or bacterial folliculitis, discoid lupus erythematosus and lichen planopilaris. Others include trauma, scarring bullous disorders (epidermolysis bullosa, bullous pemphigoid) and neoplastic disease (skin tumors and cutaneous metastasis).
Evaluation and Diagnosis
A detailed history and physical examination usually reveals the etiology of hair loss. A careful history should include the duration and pattern of hair loss, patient's diet, medication use, present and past medical conditions, family history and hair care practices.
The following are few of the features typical of different types of alopecia which helps in their diagnosis:
- Prolonged shedding and thinning of scalp hair in the temporal and parietal areas, associated with a family history of common baldness, suggest AGA.
- Rapid and diffuse hair loss suggests anagen or telogen effluvium.
- A history of physical or psychologic stress, drug use, systemic disease, recent childbirth, crash dieting or other weight loss is also associated with telogen effluvium.
- Cold intolerance, irregular menses and constipation indicate alopecia secondary to hypothyroidism.
- Easy fatigability and palpitation may indicate alopecia secondary to anemia.
- Tight braids, ponytails, elastic hair bands, rollers or other devices that place extreme and repetitive stress on the scalp hair are responsible for most cases of traction alopecia.
- Tinea capitis and psoriatic alopecia should be considered in cases of scalp flaking.
- Chemotherapy or exposure to radiation cause anagen effluvium.
- Psychologic factors may be implicated in trichotillomania.
- ‘Moth eaten’ areas on the scalp suggest sarcoidosis, syphilis or discoid lupus.
The physical examination should focus on patterns of hair loss, inflammation, scarring and the condition of remaining hairs. The ‘hair-pull’ test helps to determine the ongoing activity of hair loss. Approximately 60 hairs are grasped between the thumb, index and middle fingers from the base and firmly but not forcefully pulled away from the scalp. If more than 6 hairs (10 percent) are pulled away, the hair loss is considered to be due to abnormal shedding but if the hair count is less than 6, it is taken as normal physiological shedding.
Laboratory tests to confirm alopecia include a complete blood count to detect infection and anemia, serology for lupus erythematosus, syphilis serology, thyroid profile for thyroid dysfunction and total testosterone and dehydroepiandrosterone sulfate for hair loss associated with androgen excess and hirsutism in women. Microbiologic studies are done to diagnose bacterial or fungal-induced alopecia.
Scalp biopsies help to make or confirm a diagnosis of alopecia and can be essential in guiding therapy. It is indicated in all cases of cicatrizing alopecias and unexplained non-cicatrizing alopecias.9
Causes and medical management of Alopecia
There are many etiologic factors that cause clinical hair loss. These includes genetic predisposition, systemic illness, infection, diet, aging, physiological disturbances (such as stress), trauma, endocrine abnormalities, autoimmune disorders, chemotherapy, exposure of the hair follicles to topically-applied chemicals and structural hair defects.
Causes of androgenetic alopecia
Androgenetic alopecia is the most common cause of alopecia in both men and women.
The three recognized forms of AGA include the following:
- Male pattern androgenetic alopecia (MPAGA).
- Female pattern androgenetic alopecia (FPAGA).
- Diffuse androgenetic alopecia.
This typical baldness that accompanies aging in most men usually begins between the ages of 12 and 40 years and is frequently insufficient to be noticed. However, visible hair loss occurs in up to 30 percent over the age of 30 and more than 50 percent over the age of 50. 3
The male pattern androgenetic alopecia is characterized by recession of the hairline in the frontotemporal region, leading to thinning of the hair in the crown area and subsequent convergence of the two areas. The hair-bearing area remains in the temporoparietal and occipital regions. In FPAA, the frontal hairline is maintained while thinning occurs in the crown area. In the diffuse type, thinning is seen simultaneously over the entire scalp.
Medical management of Androgenetic Alopecia
- Treatment of AGA is either medical or surgical. The medical management focuses on decreasing androgen activity. Only two medications with proven efficacy are indicated for AGA: oral finasteride and topical minoxidil.10
- Minoxidil, a potassium channel agonist and potent peripheral arteriolar vasodilator, was originally used in the management of hypertension. Although its mechanism of action is unclear, minodixil has been observed to retard hair loss and reverse the balding process in some patients. It is approved for use as a 2% or 5% topical solution. However, the therapeutic effect is usually only temporary. Following discontinuation of the drug, the hair slowly falls out again. In addition, irritative dermatitis or contact allergic dermatitis are mentioned as adverse reactions.
- Finasteride, a selective inhibitor of 5-alpha reductase originally approved for use in the treatment of benign prostatic hypertrophy, is increasingly used in the management of alopecia. A significant number of patients have demonstrated retarded hair loss and renewed hair growth with this medication.3
- The majority of the antiandrogens are limited to use due to their potential for feminization, decreased libido,e rectile dysfunction and impotence in men.
- Drugs containing vitamins, aminoacids and trace elements may be used as supportive therapy.
- Gene therapy may become in the future another possibility for patients with AGA.
Causes of telogen effluvium
Telogen effluvium is characterized by the loss of ‘handfuls’ of hair, often following emotional or physical stressors. In postpartum effluvium, the normal shedding of hair is inhibited by hormonal influences during the last trimester of pregnancy. In the postnatal period, an accelerated loss of telogen hairs occurs within weeks to months after delivery. This delayed shedding merely allows the hairs to returns to its prepregnancy status.
Febrile-toxic effluvium is caused by severe illnesses, particularly infectious diseases marked by high fevers. It is also seen in patients who are on rapid weight reduction or starvation diets. Following appropriate therapy of the underlying disease, complete restitution of hair is possible. Drug-associated hair loss result from agents such as the progestogen oral contraceptives, high doses of vitamin A, retinoids, cimetidine, beta-blocking agents and nonsteroidal anti-inflammatory agents.
Medical management of Telogen Effluvium
- Treatment is based on identifying and treating or correcting the underlying cause of telogen effluvium.
- Following the resolution of the triggering factors, complete recovery occurs over 4 to 6 months in most cases.
Causes of alopecia areata
Alopecia areata is a common form of non-scarring alopecia that commonly affects children and adolescents although it may appear equally in males and females of any age.4 The disorder is characterized by limited alopecic patches on the scalp. The severe forms may affect the entire scalp (alopecia totalis) or body (alopecia universalis).
The hair loss in alopecia areata may be accompanied by characteristic nail changes.5 The condition may also be associated with vitiligo and organ-specific endocrine disorders, particularly thyroid disease.
Genetic factors have an important role in the development of alopecia areata and a family history is found in 10% to 42% of cases.6
Medical management of Alopecia Areata
- Immunomodulating agents used in the treatment of alopecia areata include corticosteroids, minoxidil and anthralin cream.
- For small patchy disease, intralesional corticosteroid is the treatment of choice. Triamcinolone acetonide suspension recommended up to 3 mL of a 5 mg per mL solution is injected into the mid-dermis in multiple sites 1 cm apart.6 Hair growth usually becomes apparent in four weeks. Injections are repeated every 4 to 6 weeks.
- Oral corticosteroid therapy which is seldom used because of potential adverse effects is indicated in progressive alopecia areata. The recommended treatment in adults is 40 mg prednisone per day for seven days; then gradually tapered down for six weeks.
- In addition to continuous or pulsed systemic corticosteroids, psoralen plus ultraviolet A (PUVA) have also been used to treat longstanding and widespread alopecia areata.
Potent topical corticosteroids, anthralin and minoxidil lotion are widely prescribed for limited patchy alopecia areata.
Causes of tinea capitis
Tinea capitis, also known as ‘ringworm of the scalp’ is caused by dermatophytes. Apart from hair loss, the condition causes also causes scaling, erythema and impetigo-like lesions. Classic tinea capitis occurs as single or multiple annular patches of dull, scaly alopecia containing the small stubble of many broken hairs. Although uncommon in adults, it is the most common cutaneous mycosis in children.7
Medical management of Tinea Capitis
- Oral antifungal agents such as griseofulvin, itraconazole, terbinafine and fluconazole are all effective in the treatment of tinea capitis.
- Shampoos, such as a 2% ketoconazole, 1% to 2.5% selenium sulfide, 1% to 2% zinc pyrithione, and povidone-iodine are also used as adjuncts, along with an oral antifungal. These shampoos may decrease scaling and itching substantially.
Causes of traumatic alopecia
Traumatic alopecia is hair loss caused by an injury to the scalp, usually caused by styling and grooming methods that attempt to make the hair more manageable. It is a consequence of stress traction injury from tight rollers, braiding and from overheating the hair shafts. The chemical treatments of coloring, waving and straightening hairs produce cumulative damage to the fibers when it’s too harsh, prolonged or too frequent. Subsequently, the hairs tend to break easily at the weakest points as their structural integrity is destroyed.
Trichotillomania, another cause of traumatic alopecia, is a compulsive behavior involving the repeated plucking of one's hair.8 Recognized as undesirable and senseless, this behavior is performed in response to several emotions and affects such as increasing anxiety or unconscious conflicts.
Medical management of Trichotillomania
In view of its psychologic nature, the mainstays of treatment for trichotillomania are focused on counseling and behavior modification therapy.
Selective serotonin reuptake inhibitors and other medications for depression or obsessive-compulsive disorder may be used in some cases, although no medications are FDA-approved for treatment of trichotillomania.
Causes of anagen effluvium
Anagen Effluvium is the sudden hair loss which occurs as a result of exposure to chemotherapeutic agents such as antimetabolites, alkylating agents and mitotic inhibitors used in the treatment of cancer. Hair loss usually begins 7 to14 days after a single pulse of chemotherapy and is clinically most apparent after 1 to 2 months.
The characteristic finding in this type of hair loss is the tapered fracture of the hair shafts. The hair shaft narrows as a result of damage to the matrix and eventually, the shaft fractures at the site of thinning.
Surgical hair restoration is the only permanent method of treating alopecia. The concept behind all forms of surgical hair restoration is redistribution of hair rather than addition of new hair. Surgical treatment of alopecia includes hair transplantation (macrografting and micrografting), bald scalp reductions and scalp-flap surgery.
Hair transplantation, the most common hair-restoration procedure, is a technique in which hair follicles are harvested from the occipital (back) and lower sides of the scalp, and re-transplanted in the frontal bald area.11 There are different techniques of hair transplantation. The typical doll-hair tufted effect of old macro-grafts has been replaced with micro-graft shift. Micrografts consist of 1or 2 hairs per graft and minigrafts contain 3 to 8 hairs per graft. The transplanted hair follicles appear to grow in the immediate postoperative period. Within a month, the graft follicles enter the telogen phase and are all shed.
The hair improves in quality and quantity over the subsequent 2to 4 months and stabilization in the growth occurs at about 1 year. Hair grafting has a high success rate and patient acceptance. It can be performed in the outpatient setting with little surgical preparation or specialized setup and has a low incidence of complications.
Today, follicular-unit grafting is the gold standard for hair transplantation. Follicular unit transplantation is a method by which hair is transplanted exclusively in its naturally occurring individual follicular units.12 Harvesting follicular units directly from the donor area by using punches is described as follicular unit extraction technique, and it eliminates the need for excision of a hair-bearing strip.13
Bald Scalp Reduction
Although hair transplantation is by far the most commonly performed type of surgical hair restoration procedure, some patients may be candidates for scalp reduction or scalp flaps. The procedure is recommended in selected patients. The scalp reduction procedure can be performed with or without scalp expansion.
Bald scalp reduction technique involves the excision of alopecic scalp. The excised area typically consists of the crown and occasionally extends anterior to the middle scalp. Most surgeons recommend options other than bald scalp reduction for treating hair loss on the middle and posterior scalp as it is difficult to reduce substantial areas of bald scalp without causing abnormal hair growth, scarring and marked patient discomfort .
Scalp flap surgery is another type of hair restoration surgery. In this technique, a single scalp flap can contain as many as 10,000 hairs, resulting in the creation of a dense hairline in just 2to3 procedures performed in an interval of several weeks. The procedure is rarely performed today as it requires a skilled and experienced surgeon and a highly motivated patient. In the hands of a well-experienced surgeon, scalp flap surgery can be a highly successful approach to hair restoration in carefully selected patients for its ability to create a dense hairline in a very short period.
Impact of Modern Lifestyle on Alopecia
While there are several genetic factors which determine a person's susceptibility to alopecia, the increase in cases of baldness among the population of Japan after World War II demonstrates that hair loss can be influenced by change in the diet and lifestyle. Increased fat or caloric intake, decrease in aerobic exercise, increase in stress and general ‘westernization’ was associated with a dramatic increase in the incidence of male pattern baldness.
The fast harried lifestyles of today compel us to compromise in the quality and quantity of our diet. In addition, emotional pressure can cause health complications which subsequently have an adverse impact on the quality of our hairs. Further, negligence of hair hygiene and excessive dandruff problem contributes to the hair loss.
The dramatic change in current lifestyle has contributed to the increase in various diseases. The medications and medical treatment undergone by a patient also contribute to hair loss.
There are certain medications, especially those drugs used for treatment of gout, arthritis, depression, heart problems, high blood pressure and cancer which add to the increasing occurrences of alopecia.
- Alopecia affects men and women of all ages and often significantly affects social and psychologic well-being.
- Androgenetic alopecia, one of the most common forms of hair loss usually has a specific pattern of temporal-frontal loss in men and central thinning in women.
- Telogen effluvium is characterized by the loss of ‘handfuls’ of hair, often following emotional or physical stressors.
- Alopecia areata, traction alopecia, trichotillomania and tinea capitis have distinctive features on examination that help in diagnosis.
- Early recognition of the cause of hair loss may facilitate timely treatment and prevent further hair loss.
- The evaluation includes a personal and family history, physical examination and laboratory investigations.
- An organized diagnostic and management strategy will help to establish the cause of alopecia and to direct the course of therapy.
- Although alopecia is usually treatable and self-limited, it may be permanent.
- Management should always involve assessment of the psychological effects of alopecia.
- Oral finasteride and topical minoxidil are the only proven medications for AGA.
- Hair transplantation is the most common hair-restoration procedure.
- Follicular-unit grafting is the gold standard for hair transplantation.
You May Also Like To Read
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2.Sperling LC. Hair and systemic disease. Dermatol Clin. 2001; 19(4): 711-726.
3.Bienová M, Kucerová R, Fiurásková M, Hajdúch M, Koláŕ Z. Androgenetic alopecia and current methods of treatment. Acta Dermatovenerol Alp Panonica Adriat. 2005; 14(1): 5-8.
4.Papadopoulos AJ, Schwartz RA, Janniger CK. Alopecia areata. Pathogenesis, diagnosis, and therapy. Am J Clin Dermatol. 2000; 1(2): 101-105.
5.Sharma VK, Kumar B, Dawn G. A clinical study of childhood alopecia areata in Chandigarh, India. Ped Dermatol. 1996; 13: 372-377.
6.Madani S, Shapiro J. Alopecia areata update. J Am Acad Dermatol. 2000; 42: 549–565.
7.Rebollo N, López-Barcenas AP, Arenas R. Tinea capitis. Actas Dermosifiliogr. 2008; 99(2): 91-100.
8.Sah DE, Koo J, Price VH. Trichotillomania. Dermatol Ther. 2008; 21(1): 13-21.
9.Madani S, Shapiro J. The scalp biopsy: making it more efficient. Dermatol Surg. 1999; 25(7): 537-538.
10.Shapiro J, Price VH. Hair regrowth. Therapeutic agents. Dermatol Clin. 1998; 16: 341-356.
11.Al-Khair YM. Hair transplantation. Saudi Med J. 2000; 21(9): 821-825.
12.Bernstein RM, Rassman WR. Follicular unit transplantation: 2005. Dermatol Clin. 2005; 23(3): 393-414.
13.Gökrem S, Baser NT, Aslan G. Follicular unit extraction in hair transplantation: personal experience. Ann Plast Surg. 2008; 60(2): 127-133.
Written by: healthplus24.com team
Date last updated: December 10, 2014