Telogen Effluvium vs Pattern Hair Loss

It can be hard to distinguish between two most common forms of hair loss but telogen effluvium and androgenetic alopecia (male and female pattern hair loss) are separate conditions. They have different trajectories and treatments. Telogen effluvium is a temporary shedding that leads to rapid amounts of shedding but usually self resolves. Pattern hair loss is a slow, progressive thinning in which the follicles themselves become smaller until there is permanent damage. Telling them apart isn’t always simple, especially as the two can happen together. So, how can you tell if your hair is shedding or thinning and which type of hair loss do you have? In this article, we’ll explore how telogen effluvium and pattern hair loss differ in how they develop and their appearance. We’ll also review how doctors tell them apart and what this means for treatment.

What is the Difference Between Telogen Effluvium & Pattern Hair Loss?

In telogen effluvium, a shock to the system pushes a large number of follicles into the resting phase of the hair growth cycle at the same time. The hairs then fall out a few months later. Whilst the hair shedding can be extensive, the hair follicles are healthy and go on to grow new hair with time.

With pattern hair loss, follicles that are sensitive to androgens (particularly DHT) gradually miniaturise. Each new hair grows back finer and shorter than the last. This can continue for years until eventually the follicle produces only a fine vellus hair or nothing at all. Pattern hair loss changes the size and lifespan of the follicle and can result in permanent hair loss.

What Does Telogen Effluvium Look Like?

Telogen effluvium causes a sudden increase in hair fall across the whole scalp, starting two to four months after the trigger. In a healthy scalp, about 85% of follicles are growing and 15% are resting at any one time. So it’s normal to lose up to about 100 hairs a day. After a trigger, as many as 70% of the growing follicles can enter the resting phase at once. The resting hairs stay attached for a while before falling which is why nothing happens for a few months. When they do it can be dramatic often people notice handfuls of hair in the shower, on the pillow and the brush. However, it’s important to understand that there are often new hairs growing underneath the ones that shed.

The common triggers are a fever or serious illness, stress, surgery, childbirth, rapid weight loss, a change in thyroid function, low iron, certain medicines and stopping the combined pill. Starting a hair loss treatment can also cause a brief shed, which is known as the dread shed. However, in about one in three people no trigger is ever identified.

Although the hair loss is diffuse, there are usually no bald patches. The shed hairs are of normal thickness and the shedding peaks then tapers off. A fine fringe of short new hairs often appears along the front hairline as the old hairs leave. In most people, hair fall returns to normal over six to nine months and the scalp thickens back up. However, recovery can sometimes be incomplete. If shedding carries on for more than six months, doctors call it chronic telogen effluvium and at this pint may consider supportive treatment or further investigation. Chronic telogen effluvium most commonly affects women between 30 and 60. In some people, it is remitting and relapsing condition so it comes and goes for years.

What Does Pattern Hair Loss Look Like?

Pattern hair loss involves a gradual loss of density in a predictable shape (hence the name). Usually there is little noticeable change in the amount of hair you shed on a day to day basis. It’s one of the most common causes of hair loss worldwide and usually runs in families. In men, it usually starts with recession at the temples and thinning over the crown. It then progresses through the stages of male pattern hair loss. In women, the frontal hairline is usually preserved and the thinning shows first as a widening parting and a smaller ponytail. It then progresses through the stages of female pattern hair loss without treatment.

The key feature of pattern hair loss is follicle miniaturisation. Under the influence of DHT, each affected follicle spends less time growing and more time resting. The hair it produces gets thinner and shorter with every cycle. This is why pattern hair loss often creeps up on people. The hair density may appear nearly normal for years but the hairs themselves are slowly getting finer. The scalp only starts to show through once enough of them have shrunk. Interestingly, the hair on the back and sides of the scalp are usually spared. This is because these hair follicles are far less sensitive to DHT.

Can You Have Telogen Effluvium & Pattern Hair Loss at the Same Time?

Yes because telogen effluvium can unmask a genetic tendency to female or male pattern hair loss. Basically, an episode of telogen effluvium shedding removes a lot of hair at once. If your follicles were already miniaturising slowly, the hair that grows back is finer than the hair that fell out. That’s why thinning around the hairline or the parting becomes suddenly noticeable. This relationship is particularly evident in people with chronic telogen effluvium or postpartum hair loss and early female pattern hair loss. After shedding settles, sufferers are left with thinner hair density than before.

How Do Doctors Tell Them Apart?

Doctors separate the two mainly by the history and exam looking particularly at timing, triggers, distribution and hair thickness. Sudden diffuse shedding with exposure to a trigger a few months before tends to point to telogen effluvium. On the other hand, gradual thinning over years and a family history usually suggests androgenetic alopecia. Looking at the pattern of the hair loss can also distinguish between the two. These can all be done in person or remotely.

For complex cases or if the diagnosis is not clear, there are a few tests that can be done to further clarify. Dermatologists may use a dermatoscope that magnifies the scalp to perform trichsocopy. In androgenetic alopecia, the hairs vary in thickness and a hair shaft thickness diversity of 20% or more as diagnostic. In telogen effluvium, the findings are the same everywhere. Blood tests can help find or rule out treatable causes of hair loss such as thyroid dysfunction or low iron. Rarely, dermatologists may perform a scalp biopsy but usually if they suspect another cause such as scarring alopecia.

What Should You Do if You’re Noticing Hair Loss?

If yoou’re experiencing hair loss, it is important to make sure there isn’t an underlying problem such as scalp infection, psoriasis or a systemic disease or medication causing it. You should also try to identify the pattern and nature of the hair loss to allow you to explore treatment options. Measures worth taking if you’re noticing hair loss include:

• Date the change: Count back three or four months from when the shedding started and look for a trigger. An illness, an operation, a new medication, a diet, a pregnancy or coming off the pill in that window. Any of these makes telogen effluvium likely.
• Look for regrowth: Short, fine, upright new hairs along the hairline a few months into a shed are a sign of telogen effluvium recovering.
• Ask your GP for help: Your GP can take a full medical history and exam to ensure there isn’t a serious underlying medical problem or any medications causing this. Ask them to do blood tests including ferritin, thyroid function and vitamin D as abnormalities in these can also cause hair loss.
• Stick to a treatment: If you suspect androgentic alopecia and gave started a treatment like topical minoxidil, stay the course. Hair regrowth treatments need at least 3-6 months to assess whether they’re helping.
• See a dermatologist if anything is unusual: Bald patches, itching, burning, scaling or loss of hair from the eyebrows point to more serious causes of hair loss and require specialist review.

How Does the Diagnosis Affect Treatment?

The diagnosis changes the treatment because telogen effluvium needs its trigger corrected and time to recover. You don’t usually need to do anything else though supportive hair growth treatments can help with recovery. However, pattern hair loss needs treatment to protect the follicles from the actions of DHT and stimulate regrowth. Without intervention, androgenetic alopecia is progressive and eventually the hair loss becomes permanent.

Telogen effluvium is a temporary disruption of the hair cycle that usually resolves once its trigger has gone. Pattern hair loss is a slow destruction of the follicle that carries on and becomes permanent without treatment. They can also occur at the same time which further complicates the diagnosis. If you are experiencing hair loss, the first thing to do is seek medical review early. This is to ensure that there isn’t an underlying medical condition or medication causing it. Your doctor can also help diagnose whether it is telogen effluvium, pattern hair loss or another condition based on the timeline and appearance.

At City Skin Clinic, we believe that hair loss treatment should always be personalised. This is why our doctors design custom hair loss treatments for men and women through our online clinic, using actives like minoxidil, finasteride, dutasteride, spironolactone and tretinoin where appropriate. To get started, book a virtual video consultation or complete our online consultation form. The journey towards great hair starts here.

This article is intended for general informational purposes only and is not a substitute for medical advice, diagnosis or treatment. Always consult a qualified medical provider for any medical concerns or questions you might have.