The causes of hair loss are varied and a correct diagnosis is essential to enable successful treatment. Androgenetic alopecia (the common balding process, male or female pattern hair loss) is the most common form of hair loss in men and women for which there are scientifically proven treatments which can slow down, stop or reverse the process. Generally the earlier treatment is instigated the better the results.

Alopecia areata affects 1% of the population at some time in their lives and usually presents as patchy hair loss. Whilst the course of this condition can be unpredictable there are effective treatments to encourage regrowth. Monitoring response to treatment is vital and so Dr Wade utilises a medical digital photography system which allows accurate, reproducible photographs to be taken at specified time intervals for comparison.

THE FACTS

• 5 million follicles in the adult man
• 1 million follicles on head & neck
• 100 000 follicles on the scalp
• Red heads > brunettes > blondes
• Shed up to 100 hairs per day
• Scalp rate of growth = 0.5mm per day (1.5cm per month)

THE HAIR CYCLE

Our hair is constantly renewing itself and this process is referred to as the hair cycle. Hairs pass through a growing phase, which on our scalp can be between 2 to 5 years, followed by a phase of involution and then a resting phase. It is normal to shed up to 100 scalp hairs a day. People with longer hair are usually more aware of shed hairs than people with shorter hair.

Each hair is shed when it is in the resting phase – sitting there waiting to be shed. When we brush or wash our hair we often notice that is the time when hair is shed – these hairs are waiting to be shed and would have fallen out over the next few days anyway. Anyone with hair loss should then not be scared to wash or brush their hair, unless they have one of the hair shaft disorders.

• Anagen = growth phase – 2 to 5 years + on the scalp (this determines how long we can grow our hair)
• Catagen = involution phase – up to 2 weeks
• Telogen = resting phase – approximately 3 months
• 86% of our scalp hair follicles are in anagen (or the growth phase) as any one time.

REQUIREMENTS FOR HEALTHY HAIR

Hair is one of the most metabolically active structures in the human body. Hair growth can be affected by:

1. crash diets with poor nutrition and dramatic loss of weight
2. low iron levels
3. severe illnesses
4. high fevers
5. certain drugs
6. stress

Women who may be dieting to keep weight under control, often vegetarian with or without heavy periods are the most at risk for low iron levels and thus a decrease in scalp hair.

THE COMMON HAIR CONDITIONS

The most common hair conditions are:

• Androgenetic alopecia – otherwise known as:
• Male or female patterned hair loss
• The common balding process
• Hereditary hair loss
• Chronic telogen effluvium
• Alopecia areata

Androgenetic hair loss in men (male patterned hair loss)

Men lose their hair or go bald in a very predictable pattern. Hair on the vertex (top of the head) begins to thin and there may be bilateral temporal recession (loss of hair at the corners of the frontal hair line). This gradually progresses with the hair in this region becoming thinner and thinner and in some people will eventually lead to complete baldness on the top of the scalp. The end-stage is hair like the stereotyped monks hair style. This is because the hairs at the back of the scalp are genetically preserved from this process of hair loss.

The reason men go thin when they suffer from androgenetic alopecia is due to the process of miniaturisation. Each time the hair follicle goes through the hair cycle it becomes smaller and smaller and thus produces a smaller hair shaft. Eventually the hair shaft is so small that it does not protrude above the level of the skin in the scalp.

Treatment

Fortunately, there is treatment available today which can either arrest or reverse the process of miniaturisation. This means the process of male pattern hair loss can be stopped and in many patients regrowth of hair can be achieved.

Female patterned hair loss (Androgenetic alopecia)

The same process of miniaturisation can occur in women to cause female pattern hair loss. That is, each time the hair follicle goes through the hair cycle it becomes smaller and smaller and thus produces a smaller hair shaft. Eventually the hair shaft is so small that it does not protrude above the level of the skin in the scalp.

Unlike men, women usually begin to lose their hair by going diffusely thin on the vertex (the top of the scalp). Sometimes temporal recession is also seen (loss of hair at the corners of the frontal hair line). Women rarely tend to go completely bald.

There are a few hair conditions that can result in generalised thinning of hair on the top of the scalp. It is therefore very important that the correct diagnosis is made before embarking on treatment for hair loss in women. This may mean that a scalp biopsy is necessary

Treatment

There is now good treatment for female pattern hair loss which is aimed at reversing the process and promoting regrowth. In recent peer reviewed research 88% of women with this form of hair loss attained a positive outcome with treatment.

Chronic telogen effluvium

This is a condition of where the hair cycle is affected rather than the size of the hair follicles. More of the hair follicles are pushed into the resting phase causing increased hair shedding and an inability to grow the hair as long. This condition is recognized more in women than men. The correct diagnosis is paramount as to the untrained eye this can look similar to female pattern hair loss.

Treatment is available for this condition.

Alopecia areata

Alopecia areata affects 1% of the population at some time in their lives and usually presents as patchy hair loss. Whilst the course of this condition can be unpredictable with complete regrowth in many cases hair loss can be more permanent in some patients.

Once again, there are effective treatments to encourage regrowth in this condition.

LESS COMMON HAIR CONDITIONS

Too much hair

• Hirsutism
• Hypertrichosis
• Hypertrichosis lanuginosa
• Universal hypertrichosis
• Naevoid hypertrichosis
• Acquired circumscribed hypertrichosis
• Porphyria
• Endocrine disturbances
• Teratogenic syndromes
• Malignancy induced hypertrichosis

Too little hair

Non-scarring

• Traction alopecia
• Trichotillomania
• Loose anagen syndrome

Scarring alopecia

• Congenital alopecia
• Hypotrichosis
• Lichenplanopilaris
• DLE
• Follicular degeneration
• Centrifugal alopecia
• En coup de sabre
• Frontal triangular
• Radiation alopecia

Abnormal hair shaft

• Monilethrix
• Pseudomonilothrix
• Pili torti
• Pili annulati
• Trichonodosa
• Menke’s syndrome
• Bjornstad’s syndrome
• Crandall’s syndrome
• Trichorrhexis nodosa
• Trichothyodystropy
• Trichostasis spinulosa
• Pili multigemini
• Bubble hairs
• Familial woolly hair
• Woolly hair naevus
• Symmetrical allotrichia
• Kinky hair
• Uncombable hair
• Straight-hair naevus
• Tricholasis
• Trichoptilosis
• Trichomalacia
• Trichoschisis
• Tapered hairs
• Pohl-pinkus constriction
• Bayonet hairs
• Hair casts

Dr. Martin Wade

Education Lead of Dermatology at BHR University Hospitals NHS Trust and Clinical Lead at The London Skin and Hair Clinic

Hair loss specialist, Trichologist, Hair loss expert, alopecia expert, hair loss dermatologist, alopecia areata, female hair loss. Skin cancer specialist, Acne Dermatologist, London Dermatologist, Australian Dermatologist, Skin cancer expert, Acne expert.