Hair

Hair

 Hair is actually a part of the skin that has its own specialised function. The human body is covered in hair, except on the palms of the hands, soles of the feet, genitals, eyelids and lips. Hair keeps us warm, and protects sensitive areas, such as the nose and eyes, from dust. The colour, curl, length, thickness and amount of hair depend on genetic factors.
Normal hair growth
Human hair grows from a root, which is the only living part of the hair. Hair gets longer by multiplying new cells in the root. As the hair grows, the cells die and harden to form the hair shaft. This is called keratinisation, because hair is made of a protein called keratin. This is the same protein that makes up skin and nails. The tough outer layer of the hair shaft is called the cuticle. Beneath the cuticle is the cortex, which makes up the bulk of the hair shaft. At the core is the soft medulla.
Hair follicles are pouch-like tubes of skin cells that contain the hair root. At the bottom of the follicle is the papilla, which supplies oxygen and nutrients to the root through a tiny artery. Typically, an individual hair grows about half a centimetre every month. Hair grows in phases, with around one in ten scalp hairs ‘resting’ at any given time.

Hair disorders

The broad categories of hair disorders include:
    Hair loss (alopecia)
    Excess hair (hirsutism)
    Hair infections
    Hair shaft disorders.
Excess hair (hirsutism)
In women, hirsutism is the growth of thick, dark hair in typically ‘male’ areas of the body such as the face, chest and back. A common cause is polycystic ovarian syndrome (PCOS). The causes of PCOS are unknown. In some cases, it seems to run in the family. For other women, the condition only occurs when they are overweight.
Hair infections
Hair infections are usually contagious, which means the infection can pass from one person to another. Hair loss is the typical result. Some examples of hair infections include:
    Ringworm – this fungal infection of the scalp typically starts as a small circle of red, itchy and scaly skin. As this ring grows, the hairs within its circumference snap off close to the scalp.
    Folliculitis – this bacterial infection of the hair follicles can cause temporary or permanent hair loss, depending on the severity and duration of the infection.
    Demodex folliculorum infection – this parasite likes to live in the follicles of the scalp and face. A severe infection can cause irritation and inflammation.
    Piedra – this fungal disease causes hard nodules to form along the hair shaft. The hair tends to snap off at the nodules.
Hair shaft disorders
Hair shaft disorders are caused by the inheritance of faulty genes, which result in either hair loss or unmanageable hair. Examples include:
    Trichothiodystrophy – the hair shaft is brittle because of inadequate elements and proteins such as sulphur and cystine.
    Pili torti – causes patches of hair loss and hair stubble.
    Menkes syndrome – the inability to properly metabolise copper causes a range of problems including brittle and unpigmented hair.
    Trichorrhexis nodosa – a split in the cortex frays and weakens the hair, causing it to split and break off.
    Trichorrhexis invaginata – also known as ‘bamboo hair’. The hair shaft has abnormal nodules. Breakages occur at these weak points.
    Monilethrix – nodules cause hair breakages. Usually, monilethrix only affects the scalp.
    Woolly hair – frizzy, tightly curled hair on a person of non-African descent.
    Uncombable hair syndrome – typically, the hair is silvery-blonde, slow to grow, dry and unusually stiff.
    Marie Unna hypotrichosis – the child is born without scalp hair, then grows coarse hair until pre-puberty when the hair falls out.

Hair loss

Hair loss (also known as alopecia) can ‘just happen’ or it may be linked to some medical conditions or use of medicines. It can be patchy or widespread, and may range from mild to severe.
Male pattern baldness (androgenic alopecia) is the most common cause of hair loss and is the result of genetic and hormonal factors. Hereditary baldness is so common that many people think it is a normal part of the ageing process.
Many men and women will be affected by hair loss at some stage in their lives. For most people, hair loss is mild and occurs later in life. However, when hair loss is premature or severe, it can cause distress. A range of treatments is available to slow or reduce hair loss and stimulate partial regrowth.
How hair grows
The human body is completely covered with hair follicles, except on the palms of the hands, soles of the feet and lips. Hair follicles are pouch-like tubes of skin cells that contain the hair root. Most follicles are tiny, and many of the hairs they produce do not grow long enough to stick out from the pore.
Hair is made from a protein called keratin. The only living part of the hair is the root (sometimes known as the bulb), which is anchored to the base of the follicle. The follicle supplies oxygen and nutrients to the root, and lubricates the hair shaft with an oily substance called sebum.
Hair is in a constant cycle of growth, rest and renewal – it is natural to lose some hair each day. Hair grows in phases. The colour, curl, length, thickness and amount of hair depend on genetic factors.
Causes of hair loss
There are many possible causes of hair loss. Some result in temporary hair loss (known as telogen effluvium), while others may have longer-term effects. Breaking or damaging the hair shaft has no effect at all on the health of the hair root.
Some causes of hair loss include:
    Severe illness, major surgery or high fever, which may lead to a period of excess hair shedding
    Hormonal changes resulting from thyroid disease, childbirth or use of the birth control pill
    Alopecia areata, an autoimmune disorder
    Medications such as those used in cancer chemotherapy or oral retinoids (powerful drugs used to treat skin conditions)
    Nervous habits such as continual hair pulling or scalp rubbing
    Rough handling – brushing too vigorously, tight rolling of hair curlers
    Overbleaching, or the use of harsh dyes and chemicals, which may cause split ends
    Burns or injuries
    Tinea capitis (ringworm of the scalp)
    Certain skin diseases such as lichen planus or lupus.
Genetic factors in hair loss
Identical twins lose hair at the same age, at the same rate and in the same pattern. This indicates that genetic factors are more important than environmental factors in causing hair loss.
Stress, diet, wearing hats, frequent washing, cigarettes and alcohol use are exaggerated as causes of hair loss.
Male pattern baldness (androgenic alopecia)
While there are a number of treatments available for male pattern baldness, there is no cure. Treatments include minoxidil lotion and finasteride tablets, which are available on prescription. Cosmetic options include camouflage sprays, wigs and hair transplant surgery.
Hair loss in women (androgenetic alopecia)
Hair loss in women produces scattered thinning over the top of the scalp rather than a bald spot. Minor patterned hair loss occurs in over 55 per cent of women as they age, but only about 20 per cent of women develop moderate or severe hair loss.
A number of treatments are available for female pattern hair loss, including topical minoxidil lotion (not recommended for pregnant and breastfeeding women) and tablets such as spironolactone, which have antiandrogen properties (they lower the levels of male hormones). These are available on prescription and require medical supervision.
Treatment for hair loss
Treatment aims to slow or reduce hair loss, stimulate partial regrowth or replace damaged hair. Surgical treatment involving hair transplantation is available from hair transplant surgeons and can be helpful for some men with advanced balding.
Non-surgical treatments include lotions and tablets. These generally need to be used continuously to maintain regrowth. If treatment is stopped, regrowth ceases and hair loss will start again. Cosmetic options include wigs and hairpieces.
A number of other treatments have been suggested for hair loss including massage, vitamin supplements, herbal remedies (such as saw palmetto), zinc, amino acids, hair lotions and tonics. None of these has been shown to promote hair growth or prevent hair loss.
There is also no scientific evidence that the use of lasers is effective. If unsure, consult with your doctor before starting treatment.
Minoxidil
Minoxidil lotion has been available in Australia since the 1970s. A number of different brands are available from pharmacies without a prescription. Drops are applied to the scalp morning and night and rubbed in. There is also a new foam preparation that appears to be easier to use and just as effective. Hair regrowth generally takes six months to appear. Patients considering taking minoxidil should tell their pharmacist if they are taking any other medicines, especially high blood pressure medication.
Minoxidil is not recommended for pregnant and breastfeeding women.
Finasteride
Finasteride is the active ingredient in the hair loss treatment Propecia, which has been available in Australia since the late 1990s. One tablet a day will arrest further hair loss in over 90 per cent of men and stimulate partial hair regrowth in over two thirds. Regrowth may be visible at six months, but can take up to two years to be visible. Side effects are uncommon, although Propecia does require a prescription from your doctor.
Finasteride is not recommended for women.
Spironolactone
This medication has been widely used to treat high blood pressure and fluid retention in Australia since the 1960s. It blocks the effect of androgen hormones. In women, androgens can cause oily skin, acne, unwanted facial and body hair, and scalp hair loss. Spironolactone can be used to treat all of these conditions, but it requires a prescription from your doctor.
Spironolactone is not recommended for men. Pregnant and breastfeeding women should not take spironolactone.
Cyproterone acetate
This medication was also developed in the 1960s. It blocks the effect of androgen hormones. It is also a weak progestogen and is used as a component of some oral contraceptives (the pill). Cyproterone acetate can also be used to treat acne, unwanted facial and body hair, and hereditary hair loss in women. Cyproterone acetate requires a prescription from your doctor.
Cyproterone acetate is not recommended as a treatment for hair loss in men.
Hair transplantation surgery
Hair transplantation is a surgical procedure for the treatment of hair loss that first became popular in the 1950s. Originally, large plugs of hair were used, which sometimes led to unsatisfactory and unnatural results.
Currently, very small mini- and micro-plugs of skin, containing one to five hairs, are used. Unlike the original large plugs, this modern technique does not produce very thick or dense hair growth. It appears more natural and, in many cases, is undetectable as a transplant.
Types of hair loss that respond best to hair transplantation include:
    Androgenetic hair loss in men – this is the most common type of baldness that can be helped by hair transplantation
    Hair loss due to accidents and operations.
Hair plugs are taken from the back or sides of the scalp where the hair is less likely to fall out. These plugs are transferred to the bald areas and placed in such a way that they receive adequate blood flow during the healing process. The transplant session may take several hours.
One to three months later, more grafts can be added. Several treatments are required to give a progressive increase in the amount of hair. Hair will regrow in the area from which the hair plug was taken for transplantation.
A sedative is usually given prior to the procedure. Local anaesthetic is also used at the hair removal (donor) and recipient sites. As the anaesthetic wears off, you may notice some discomfort. This can be eased with simple pain-killing medications.

Complications of hair transplantation

 Possible complications of hair transplant surgery include:
    Infection – this can occur because the skin is broken to perform the procedure. It can be treated with antibiotics.
    Bleeding – this is usually controlled through careful postoperative care.
    Scarring – approximately 11 per cent of the population have a tendency to scar.
    Temporary, operation-induced hair loss – known as telogen effluvium, can occur with hair transplantation as well as some other operations. It occurs in approximately five per cent of patients.
    Unacceptable cosmetic results – scarring and unacceptable cosmetic results are more common when hair transplants are carried out by inexperienced practitioners.
Seek advice from a specialist dermatologist
Many hair clinics offer hair transplantation. However, specialist dermatologists are best qualified to properly advise about this surgery, as they generally have the most knowledge about hair in health and disease.