What is Acute Telogen Effluvium?
Acute telogen effluvium (ATE) causes excessive and dramatic hair shedding. It may begin suddenly. It may lead to the loss of up to 50% of your scalp hair. Fortunately, it should recover completely over a 3-6month period.

Why the shed?
Hair does not grow continuously. It grows in cycles. Eyebrow hairs grow for 2 months and then cycle. Armpit hairs row for 6-9 months and then cycle. Scalp hairs grow on average for 36 months and then cycle. As all hair grows approximately 1 cm per month, the duration of the growth phase of the cycle determines hair length on different parts of our body. 

At the end of the cycle, the hair bulb dies, but remains anchored to the follicle for 3 months, before a new hair is produced that pushes the old one out. That means that on the scalp, the hairs that fall out today are the ones that died 3 months ago, and the hairs scheduled to fall out every day for the next 3 months are already dead. 

Over the course of 3 years (or 1100 days), every hair on your scalp dies and is replaced. As there are approximately 100,000 hairs on your scalp, you need to shed 100 hairs every day to make room for the new ones. Most of this loss goes unnoticed, but if you lean forward and vigorously scratch your scalp for 2 minutes, you will see them. 

If an illness or an injury to the hair bulb causes them to die prematurely, hair loss is usually delayed for 3 months until the new hairs grow and push the old ones out. While cancer chemotherapy can cause the hairs to fall out sooner, but this is an exception rather than the rule. 

What will you notice if you develop telogen effluvium?  
• excessive shedding with hair washing (clogging the shower) and brushing 
• increased hair on clothes/ pillow 
• hair coming out in big amounts when touching or styling 
• generalised hair volume decreasing (sometimes more noticeable at the temples)
• if you have long hair, the loss will be more noticeable than if you have short hair
• women who tie their hair back in a pony tail will notice their pony tail getting thinner
• hair can thin at other body sites (eyebrows, eyelashes, pubic)
• scalp discomfort (burn, pain, itch) may be present

We developed this visual scale to show you what amount of hair loss is normal and what amount is excessive and might indicate telogen effluvium.  

What are some of the triggers that cause hair bulbs to die, and then fall out 3 months later? 
• high fever or severe illness 
• surgery
• trauma
• post pregnancy ( a third to half of pregnancies)
• sudden weight loss or dietary change 
• big bleed (haemorrhage)
• medication (stopping or starting any hormones, retinoids, antidepressants, anticonvulsants, B blockers etc)
• endocrine disorder (eg thyroid disease)
• severe sunburn
• disease affecting the scalp (eg psoriasis/ hair dye allergy)

One third of people are unable to identify an inciting trigger. Many people attribute their hair loss to emotional stress but doctors are not very good at measuring emotional stress and we are unable to prove that every day stressors can induce hair loss.

Sometimes ATE is an early warning sign for female pattern hair loss (FPHL). If your ATE does not recover after 6 months, or if the recovery is incomplete, or if there is no clear cause for your ATE or if you get multiple episodes of ATE, we recommend you see your dermatologists to assess whether you are in the early stage of FPHL. 
 

Who gets ATE?
ATE can affect people of any age, any race and both men and women can be affected.
 

How is it diagnosed?
• Often your doctor can make a diagnosis just by talking to you and examining your scalp. 
• A dermatoscope examination of the scalp can help exclude other causes of hair loss that can present with hair shedding. 
• Sometimes the nails can show signs of damage with a groove running across the nail plate (Beau lines). This is because both nail and hair growth are affected by the initial trigger. 
• A scalp biopsy may be required if the diagnosis remains unclear. 
• Bloods tests may be needed to identify other causes of sudden hair loss or factors that can contribute to hair loss. 
 How to treat?
In most cases the hair will return to its former state unless there is another underlying hair condition that may be exposed or unmasked such as early male or female pattern of hair loss. 

Vitamins, amino acid supplements and biotin may be helpful, especially if you don’t have a balanced diet or stable body weight. If you are iron deficient, iron replacement occasionally helps, but iron replacement therapy is rarely the entire solution. 

Minoxidil (topical, oral or sublingual) will speed up both resolution of shedding and accelerate hair regrowth. Shedding can temporarily increase 2-8weeks after initiating minoxidil treatment as new hair growth pushes out 
some of the already dead hair bulbs. 

Stemoxidine, available as a topical solution, may also increase hair follicle density but is not specific treatment for ATE. Dramatic hair loss often causes a lot of anxiety and this must be acknowledged and addressed. Fortunately, we do not believe that the anxiety will worsen the hair loss. 

Involving a hairdresser or stylist can help minimise the cosmetic effects of the hair loss while regrowth is awaited.