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Temporal Triangular Alopecia: Causes, Symptoms and Treatment
Mr Ulf Kienecker (GMC)
Medically reviewed by
Mr Ulf Kienecker (GMC)
Updated on March 6, 2025

Temporal triangular alopecia (also known as congenital triangular alopecia) is an uncommon hair loss condition which affects 0.11% of the worldwide population [1]. Its main symptom is a bald spot on your temple or frontal area. Usually detected in childhood, this condition remains unchanged throughout life [2]. Since the hair loss is often mild, researchers believe most cases go undiagnosed. 

However, if your temporal triangular alopecia bothers you, it is easily fixable with a low volume hair transplant. Find out all about this condition, including:

  • What temporal triangular alopecia is
  • The causes and symptoms of temporal triangular alopecia
  • Who can get temporal triangular alopecia
  • How to treat temporal triangular alopecia

What is temporal triangular alopecia?

Temporal triangular alopecia is also known as congenital triangular alopecia. It is a non-scarring, non-inflammatory type of hair loss which usually manifests around the temples or the frontal area of your scalp. In this condition, the hair follicles in the affected area are miniaturised, so they either don’t produce any hair at all or only produce very small (vellus) shafts. 

Research shows that 33.6% of temporal triangular alopecia cases are discovered at birth and 55.8% more between the ages 2-9. Only 3.8% are first noticed in adulthood [3][1]. 

In most cases (79%), this condition only affects one side of the head. However, some people experience symmetric bald spots on both sides (18.5%). And while congenital triangular alopecia normally affects your temples and frontal area, it can very rarely affect the back of your head instead[1]. 

What causes congenital triangular alopecia? 

The causes of congenital triangular alopecia are currently unclear. It is often inherited from a family member, suggesting that it is likely genetic, though no specific genes involved in this process have been uncovered [3].

Some researchers believe triangular alopecia may be caused by a dermatological defect [1]. This may also have a genetic component, but more research is necessary to determine the mechanism of this condition. 

Male adult with temporal triangular alopecia
Male adult with temporal triangular alopecia

What are the symptoms of temporal triangular alopecia?

The main (and often the only) symptom of congenital triangular alopecia is a triangular, oval or lancet-shaped bald spot in the frontal or temporal area of the scalp. These bald spots are often 2-4 cm in length [4] and reveal no hair growth or only miniaturised hair. In rare cases, the hair isn’t fully missing, but it is smaller and darker-coloured than the surrounding area [1]. While this type of alopecia is usually contained to one side of the head, in almost 20% of patients, it can be found on both sides [1]. 

A defining feature of temporal triangular alopecia is that it does not change size and shape over time. Additionally, it doesn’t spread to other areas of the scalp or produce inflammation, redness, pain or discomfort. In rare cases, patients can experience tingling in the affected area [5].  

Who is more likely to get congenital triangular alopecia?

This type of hair loss may be hereditary, as medical history often shows it runs in families [1]. This means that if one of your parents (or another close biological relative) is experiencing this condition, you likely have a greater chance of developing it as well. 

There don’t seem to be any significant gender differences when it comes to congenital triangular alopecia, so men are as likely to experience it as women. 

White patients may be somewhat more likely to develop congenital triangular alopecia, but the condition has also been reported by Asian and Black patients [1]. 

Congenital triangular alopecia sometimes develops alongside other conditions, such as Down’s syndrome, bone and tooth abnormalities or congenital heart disease [5]. However, these occurrences are rare. If you have temporal triangular alopecia, it doesn’t necessarily mean you also have another condition [3].  

Man getting dermoscopy to diagnose triangular alopecia

How is temporal triangular alopecia diagnosed?

Congenital triangular alopecia can often be diagnosed visually with a simple dermoscopy, alongside an examination of your medical history and symptoms [1][5][6]. A scalp biopsy is only performed in rare and complex cases. This can rule out other similar conditions when the clinical examination isn’t conclusive [1].

During the clinical examination, your trichologist will check for a patch of miniaturised (or absent) hair without other symptoms, such as inflammation, lesions, broken hair shafts or coloured dots on the scalp. 

congenital triangular alopecia vs alopecia areata
Little girl with congenital triangular alopecia (left) and woman with alopecia areata (right)

What other conditions can congenital triangular alopecia be mistaken for?

Congenital triangular alopecia (CTA) can be mistaken for several other hair loss conditions. Here are some of the most similar and how you can tell them apart from temporal triangular alopecia [1]:

Other similar hair loss conditionsHow to tell them apart from CTA

Alopecia areata 

An autoimmune condition that causes patchy hair loss, alongside scalp inflammation, broken hairs and black or yellow dots on the scalp
The smooth bald spots on the scalp caused by alopecia areata can look like CTA. However, these spots often resolve over time, only to flare up again later, while CTA does not. Also, CTA almost always develops on the frontal area and does not cause inflammation, broken hairs or dots on the scalp.

Androgenetic alopecia 

A very common genetic and hormonal condition also known as male pattern baldness or female pattern baldness. It is  progressive and starts with a receding hairline and temple hair loss in men and a widening of the midline parting in women.
CTA only affects a small area on the hairline or temple area (usually on one side) and it does not progress over time. It does not affect your crown or midline parting. Androgenetic alopecia is diagnosed in late adolescence or adulthood, while CTA is usually discovered in early childhood.

Traction alopecia 

This type of alopecia is caused by tight hairstyles or heavy hair extensions worn for extensive periods. It mostly affects the fringe or frontal area of your scalp.
Traction alopecia is most often temporary and resolves itself after the stressor is removed, while CTA is permanent. Moreover, traction alopecia is often accompanied by inflammation, bumps, redness or itching, which do not occur in CTA.

Trichotillomania 

This is a psychological compulsion to repeatedly pull out hair from a part of your scalp, eventually damaging the hair follicles. It can lead to a (usually temporary) bald spot in the affected area.
Trichotillomania often manifests with broken hairs, scalp redness and tenderness around the bald spot. It often resolves once you stop pulling out your hair. CTA is permanent and has no other symptoms except a bald patch and, rarely, some scalp tingling.
Hair transplant for congenital triangular alopecia

Patient with congenital triangular alopecia before and after 500-graft FUE hair transplant

How can temporal triangular alopecia be treated?

In most cases, temporal triangular alopecia is too mild to make those who experience it seek treatment, which is why it is also often underdiagnosed. However, treatment options exist. 

The most effective (and the only long-lasting) way to treat temporal triangular alopecia is a permanent hair transplant. This simple, outpatient surgery involves taking some healthy hair follicles from the back of your head and inserting them into the bald spot on your temple area. Since this only requires a few hundred hair grafts (normally around 250-500), hair transplant costs should be lower than average and recovery should be relatively easy.

Alternatively, while more research is needed to study the effect of different hair growth medications on congenital triangular alopecia, one treatment seems promising. A few case studies reported an improvement in the number of normal-sized terminal hairs in the affected area after treatment with topical Minoxidil [2][7]. However, the effects of Minoxidil only last as long as you take the medication.

Is temporal triangular alopecia permanent?

Yes, temporal triangular alopecia is a permanent condition. It doesn’t change throughout your lifetime and there are no recorded cases of spontaneous remission. The only way to curb this type of hair loss is by treating it with Minoxidil or getting a hair transplant. 

However, the good news is that in most cases, the hair loss produced by this condition is mild and easy to mask. Most people feel no need to get treatment for it. 

Woman masking her temporal triangular alopecia

How can you mask temporal triangular alopecia?

There are several good ways to camouflage your congenital triangular alopecia. Here are some of the best.

Choose a flattering hairstyle

The hair surrounding your bald spot is your most effective camouflaging tool. Choosing a slightly longer, side-swept hairstyle can be enough to render your bald patch invisible.

Since congenital triangular alopecia usually causes temporal or frontal balding, you might also find some inspiration among these female hairstyles for a receding hairline (or, respectively, these male hairstyles for receding hairlines).

Use a coloured hair thickening spray 

Using a coloured hair thickening spray on your bald spot can reduce the colour contrast between your hair and skin. Moreover, the microfibres in the spray cling to vellus hairs on your problem patch, creating the illusion of hair coverage. This will make your affected area less visible, especially from a distance. It works best for people wearing short hairstyles.  

Wear a hat or headband

A cap, hat, headband, head scarf or beanie can fully hide your bald spot. For minor hair loss, an accessory such as a larger decorative hair clip can help cover the affected area.   

Get a small hairpiece

If your hair loss is more significant, you may be able to order a custom-made hairpiece to cover the bald spot. Natural hair options can look quite lifelike, and modern attachment systems can be semi-permanent.

Try scalp micropigmentation

Scalp micropigmentation (SMP) is frequently used to mask hair thinning on your scalp. A type of hair tattoo, in SMP the technician injects small dots of pigment into your bald spot, replicating natural hair growth patterns. This reduces the colour contrast between your scalp and hair, making your bald area less visible. It works best if you wear a short haircut, such as a buzzcut or a pixie cut. 

However, to avoid SMP regrets, note that this procedure does not work well for people with lighter hair shades, such as blondes or redheads, as there are no matching pigment options. 

Ben Stokes visiting the Wimpole Clinic after his successful hair transplant

Would you like to treat your temporal triangular alopecia?

If you are experiencing temporal triangular alopecia and have grown tired of hiding your bald patch, we are here to help. Book a consultation with one of our top trichologists at your most convenient clinic location. They will assess your hair loss and work with you to determine the most appropriate and effective treatment.

If you are interested in getting a natural-looking hair transplant, our experienced hair doctors will assess whether you can benefit from this procedure. The Wimpole Clinic is one of the leading hair transplant facilities in the UK, with a 50-year legacy of hair restoration excellence. See our results for yourself in our before and after hair transplant photo gallery.

Temporal Triangular Alopecia: Causes, Symptoms and Treatment, Wimpole Clinic

Frequently asked questions 

If you would like to discover more about congenital triangular alopecia, here are the answers to some frequently asked questions.

Yes, despite the name of this condition, your bald spot doesn’t have to be triangular, it can also be oval, round or lancet-shaped [1]. It takes its name from the most common form of presentation, which is triangular [6]. 

There are currently no recorded cases of temporal triangular alopecia on the crown. It can rarely occur at the back of your head, but if you see a bald spot on your crown, the best thing to do is see a trichologist. They can help rule out other types of alopecia. 

Since the cause of congenital triangular alopecia is still unclear, it is hard to say if anything could prevent it. However, since most of the evidence appears to point towards a genetic nature, this condition is likely not preventable (but more research is needed to prove this). 

At this time, there is no evidence that the male hormone dihydrotestosterone (DHT) (which causes hair miniaturisation in androgenetic alopecia) is a factor in congenital triangular alopecia. Since Finasteride works by lowering the DHT levels in your blood, there is no proof it can help curb or reverse this condition. 

Mr Ulf Kienecker (GMC)
Medically reviewed by Mr Ulf Kienecker (GMC)Updated on March 6, 2025
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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