Alopecia is a term used for all kinds of hair loss, diffuse or localised, and can affect any part of the body. Hair loss can be caused by various reasons and is broadly divided into scarring or non-scarring type.

Scarring alopecia typically causes irreversible hair loss due to destruction of the hair follicle and affects approximately 3% of hair loss patients. Sometimes, if diagnosed and treated in early phase, regrowth of hair is possible.

Non-scarring alopecia is more common than the scarring variety and often is comparatively easier to treat.

Majority of hair loss we find in men is related to hormones (androgens) and genetics and is known as Androgenetic Alopecia. This is characterised by a receding hairline and/or hair loss on the top and front of the head.

Baldness here is caused by genetically determined sensitivity to the effects of Dihydrotestosterone (DHT) in specific areas of scalp. DHT shortens the growth phase of the hair cycle from 3-6 years to a mere weeks to few months. DHT also causes miniaturisation of the hair follicles which leads to fewer and finer hair being produced, leading to minimal or no hair growth at all.

The area typically spared is the back and side of the scalps, also known as the ‘safe zone’ or ‘permanent area’.

Norwood scale of Male Pattern Baldness

This is a distinct form of hair loss affecting women where there is diffuse thinning of scalp hair due to increased shedding or reduction in hair volume or both. It is unusual for women to bald in a pattern similar to men unless there is excessive androgen production in the body.

FPLH has a strong genetic predisposition. It more commonly affects women after menopause. Hair loss initially occurs in short lasting episodes interspersed with longer periods of no hair loss or stability. Without medication, it tends to worsen over the next few decades of life.

Few of the most common skin conditions which may cause hair loss are as follows

1. Discoid Lupus Erythematosus: This is an autoimmune condition and if it affects the scalp, then it can unfortunately cause permanent hair loss. Patients may first find itchy tiny bumps on scalp that eventually resolve into permanent scarring. If treated early, it may be possible to make the disease dormant or less active, but it can unfortunately reactivate at any time. Hair transplantation may work but only after a dermatology opinion stating that the disease has stopped or has burnt out.

2. Severe scalp infections (Both fungal & bacterial): Depending on the severity of the infection, hair loss may be of scarring or non-scarring type and again early diagnosis and treatment is very important to reduce the chances of scarring and hair loss.

3. Lichen Planopilaris: This is an autoimmune inflammatory skin condition which can affect the scalp and cause scarring alopecia. Middle aged females are more affected than men. There are often signs of inflammation on the scalp which the patient can experience in the form of itching, burning and shedding of hair. On examination, tiny red bumps can be seen surrounding the hair follicles. Hair transplant may be effective in minority of patients only, but even in them, the transplanted hair can be lost in case the disease reactivates.

Chemicals used in various hair products can damage the scalp. Some damage the hair shaft, but few can cause scalp damage too in form of chemical burns, but, fortunately very rare. Damage is often related to the duration of use and the strength of these products.

Scald and Burns on the scalp can cause permanent hair loss as the hair roots are completely destroyed. Success with hair transplants in these cases depends on the various factors like thickness of scar tissue and blood supply of the scar tissue.

This condition can affect any age group and is thought to be mediated by an autoimmune process. There are one to multiple patches of round bald areas which appear suddenly. In severe cases, this can affect the whole scalp or the whole body.

Sometimes it responds to medical treatments and sometimes it resolves spontaneously without any intervention.

Traction alopecia is caused due to mechanical pull or tension on the hair shafts, often due to tight hairstyles. If the issue is addressed early and cause of traction taken away, hair grows back, but if cause is not addressed and the constant pull on the hair shaft continues, then over time hair loss becomes permanent. This kind of hair loss is commonly seen in Afro-Caribbean women and men from the Sikh community.

Hair transplantation offers a solution as long as the cause of traction is removed

This is also called Hair-Pulling Disorder. It’s a mental disorder which involves the recurrent pulling of hair from scalp or other body areas like beard, eyelashes, eyebrows etc. There is an irresistible uncontrollable intense urge to pull out the hair and a sense of temporary relief and satisfaction once the hair has been pulled out.

On examination, there are irregularly shaped bald patches with varying hair lengths and may feel stubbly. There can be irreversible scarring in worst cases.

There are various medications known to cause hair loss like warfarin, certain water tablets, certain epilepsy medications, hormonal contraceptives etc. Thankfully in most of these cases, hair loss reverses once the medications have been stopped.

Chemotherapy also causes hair loss. These targets fast growing cancer cells, but due to the fast growing nature of hair cells, they unfortunately also become a target of these treatments. Reducing the growth rate of hair by using cooling therapies can reduce the hair loss significantly. With chemotherapy, hair usually grows back after the treatment cycle is completed.

Radiotherapy causes hair loss only if the hair containing area is exposed to radiation, but unlike with chemotherapy, hair loss due to rays is irreversible.

Stress can be physiological or emotional and can take a toll on your hair. Physiological stresses like interim pregnancy, lactation, vitamin deficiencies, hormonal imbalances or deficiencies, surgery, sudden weight changes etc can cause hair loss. Hair loss is often becomes evident few months after the actual stress Emotional stress can also cause hair loss.

Hair loss in these cases is mostly temporary and is due to shedding of resting hair, known as Telogen Effluvium. New hair usually continues to grow.
In a normal person, about 85% of hair follicles are is actively growing (Anagen hair) & rest 15% are resting hair (Telogen Hair). Anagen phase usually lasts for 3-4 years followed by a resting phase of approximately 4 months. The resting or Telogen hair has a bulb at tip and the new Anagen hair begins to grow under this resting Telogen hair and pushes it out. Therefore it is normal to lose between 50-100 hairs a day as part of the normal hair growth cycle.

When there is any stress/ shock to the body, as many as 60-70% of Anagen hair can go into the resting phase, thus reversing the ratio and causing Telogen Effluvium. It is only about 2-4 months r the shock that the new hairs push out the resting hair clubs (Telogen Hair) & increased hair loss is noticed some months after the initial shock.

Thus interestingly this type of hair loss is actually a sign of new hair coming through.