What Is Loose Anagen Syndrome, And Is It Treatable?

One of the lesser-known conditions that can cause hair loss is loose anagen syndrome (LAS), a type of hair disorder that can cause hair to become “loose” and easy to pull out. 

The good news? It doesn’t usually result in complete hair loss.

Below, we explain what loose anagen syndrome is and outline the factors that can cause it to develop. 

We also go into the most effective treatments for loose anagen syndrome, including hair loss medications and simple habits to prevent hair shedding.

Loose anagen syndrome, or loose anagen hair, is a hair growth disorder. People with LAS have hairs loosely anchored to their scalp, which means their hair falls out easily and painlessly when pulled.

It’s most common in children, but it can also affect adults. When it does occur, it can cause ​​diffuse hair loss that gives your hair a thin appearance. 

Your hair grows as part of a multi-stage process called the hair growth cycle. In the anagen phase, which typically lasts two to six years, hair grows from the hair follicles to its full length.

After reaching its full length, normal anagen hair passes through the catagen (transition) and telogen (rest) phases. Then, it fully detaches from the scalp and sheds before new hair takes its place.

In people with loose anagen syndrome, hairs in the anagen phase don’t properly anchor into the scalp. Because of this weak bond, these hairs shed easily.

Unlike most forms of male hair loss, such as androgenetic alopecia or telogen effluvium, loose anagen syndrome isn’t very common — it affects around two out of every million people annually.

Because loose anagen syndrome isn’t common, it’s often mistaken for other hair growth issues or conditions that can cause hair shedding. It also isn’t the same as trichotillomania, a mental health disorder characterized by deliberate hair pulling.

Researchers don’t know exactly how loose anagen hair syndrome develops or the factors that cause this hair condition to affect specific people. 

Evidence suggests that loose anagen syndrome results from defects that affect the growth of the inner root sheath — one of the first parts of the hair shaft to grow out from the hair follicle.

Hair grows through a process called keratinization, in which cells produce large amounts of the protein keratin. The inner root sheath is the first layer of the hair to keratinize.

When the inner root sheath develops too early —  also known as premature keratinization —  it may result in a weaker bond between the inner root sheath's cuticle and the hair shaft's cuticle.

This weak bond reduces the hair’s strength, making it easier to pull out from the scalp. 

In one study, researchers found that loose anagen hairs could be pulled out from the scalp with less than a third of the force required to pull out healthy hair.

This condition can occur spontaneously or due to one or several inherited gene mutations.

Research suggests that people with loose anagen hair syndrome often have a family history of other forms of hair loss, such as alopecia areata.

Although loose anagen syndrome usually occurs on its own, it can sometimes show up with other hereditary or developmental disorders, including:

• Coloboma 

• Ectodermal dysplasia, ectrodactyly, and cleft lip or palate syndrome

• FG syndrome

• Hypohidrotic ectodermal dysplasia (HED)

• Nail-patella syndrome

• Noonan syndrome

• Trichorhinophalangeal syndrome

• Uncombable hair syndrome

The main symptom of loose anagen syndrome is hair that’s weakly attached to the scalp and easy to pull out. 

Cases of loose anagen syndrome are typically sorted into three categories:

• Type A causes short hair that can appear very thin due to reduced hair density.

• Type B leads to curly, patchy, and sparse hair that’s difficult to control. People with this type of LAS might have unruly hair or a “bedhead” appearance.

• Type C leads to hair that presents with normal thickness and density but sheds excessively. This type of loose anagen syndrome occurs in adults.

Unlike male pattern baldness or scarring hair loss, which cause permanent damage to your hair follicles, loose anagen syndrome usually causes temporary hair loss. 

Most cases of loose anagen syndrome only affect hair on the scalp and not eyelashes, eyebrows, or body hair.

If you think you may have loose anagen syndrome, it’s best to talk to your healthcare provider or schedule an appointment with a dermatologist.

A dermatologist can usually diagnose loose anagen hair syndrome after a brief physical exam. 

To test your hair for LAS, a dermatologist may:

• Do a hair pull test to see if they can easily pull hair from your scalp without causing significant pain.

• Perform a microscopic examination using light microscopy (trichogram) to look for signs of loose anagen syndrome, such as misshapen hair bulbs, ruffled cuticles, and absent inner or outer root sheaths.

If most of your extracted hairs show signs of developmental abnormalities, you'll generally receive a loose anagen hair syndrome diagnosis.

Most of the time, loose anagen hair syndrome improves on its own and doesn’t require active treatment. 

If you have noticeable hair shedding from LAS, your healthcare provider may suggest using an FDA-approved topical hair loss medication such as minoxidil.

Minoxidil works by stimulating blood flow and prolonging the anagen phase of the hair growth cycle. 

Although it can take several months to produce results, it’s considered an effective first-line therapy for loose anagen syndrome.

Because loose anagen syndrome isn’t caused by dihydrotestosterone (DHT), medications for male pattern baldness like finasteride don’t work to treat this form of hair loss. 

Your healthcare provider may suggest you wash, dry, and comb your hair gently to prevent loose anagen hairs from falling out. 

It may also help to avoid tight hairstyles that pull on your hair roots.

Let’s recap what we know about loose anagen syndrome:

• It’s an uncommon hair growth disorder that can cause your scalp hairs to fall out easily, giving your hair a thin appearance. 

• It’s typically a pediatric condition but sometimes affects adults.

• It’s treatable with minoxidil, a proven hair loss treatment that encourages hair growth. 

If you think you might have loose anagen syndrome, consider talking to your healthcare provider or scheduling an appointment with a dermatologist. 

You can learn more about conditions that cause hair loss in our detailed guide to the causes of hair loss in men.