Alopecia Areata vs Scarring Alopecia: Telling Them Apart — Is It Really Alopecia Areata?

Three-Line Summary

• Alopecia areata is a non-scarring form of hair loss in which the hair follicles are still alive and hair can grow back once the inflammation settles, whereas scarring alopecia is hair loss in which the follicles are destroyed and turn into scar tissue. Because hair does not grow back where scar tissue has already formed, the goal of treatment in scarring alopecia is to protect the follicles that remain.
• In clinic we look at three things first: whether the follicular openings (the pores hairs grow from) are visible or have disappeared, whether there are symptoms such as itching, stinging or pain, and whether the patch is filling in or widening with a jagged outline. When it is unclear, we confirm with scalp dermoscopy (a magnified examination of the scalp) and a biopsy.
• Even with the same intralesional steroid injection, in alopecia areata it is placed across the whole patch to help regrowth, while in scarring alopecia it is placed only at the edge where inflammation is ongoing, to prevent further loss. This is why telling the two conditions apart at the start matters as much as the treatment itself.

Why Tell Them Apart at the Start — A Question of Whether the Follicles Remain

The essential difference between the two conditions is whether the hair follicles remain. Alopecia areata is a non-scarring form of hair loss in which the follicles are alive, so hair can grow back once the inflammation is brought under control. Scarring alopecia is hair loss in which the follicles of the scalp are destroyed by inflammation and replaced by scar (cicatricial) tissue, and hair does not grow back from follicles that are already gone.

So the goal of treatment differs from the outset. Treating scarring alopecia is not about bringing back hair that has been lost; it is about preventing any further loss of the follicles that remain now. This is why working out at the start whether it is alopecia areata or an early stage of scarring alopecia matters as much as the treatment itself.

They Can Look Alike Early On

The conditions that fall under scarring alopecia can also look like round bald patches early on and be confused with alopecia areata. Over time they shift toward the typical scarring picture: shiny scars and disappearing follicular openings. What we look at to tell them apart during the period when they look alike is the focus of this article.

Which Conditions Fall Under Scarring Alopecia?

Scarring alopecia is not a single disease; it is a name that groups several conditions together. Primary scarring alopecias are divided according to whether the inflammatory cells attacking the follicle are lymphocytes or neutrophils. In Korea, of the conditions below, lichen planopilaris and discoid lupus erythematosus are the ones we watch for in particular in cases that were thought to be alopecia areata and turn out to be scarring alopecia.

Which Part of the Follicle Does the Inflammation Target?

Why hair grows back in one and not in the other is explained by which part of the follicle comes under attack. For hair to grow back, the stem cells in the bulge, a region midway along the follicle, have to be preserved.

Alopecia Areata — A Follicle Whose Immune Privilege Has Broken Down

A normal hair follicle has what is called immune privilege, a protection that keeps immune cells from attacking it freely. In alopecia areata this protection breaks down, CD8+ NKG2D+ T cells surround and attack the hair bulb, and in tissue samples lymphocytes are seen clustered around the hair bulb in what is called a "swarm of bees" pattern. This is why alopecia areata is most accurately described as an autoimmune condition.

Genetic predisposition, stress, infection, thyroid disease and other autoimmune diseases are all mentioned in connection with it, but in most cases there is no single cause that can be pinpointed as the one reason. The important point is that the upper part of the follicle, where the stem cells are, is largely preserved. That leaves room for hair to grow back once the inflammation settles, so it counts as a relatively reversible form of hair loss.

Scarring Alopecia — The Upper Follicle, Where the Stem Cells Are, Is Destroyed

In scarring alopecia the target of the inflammation is different. What comes under attack is the upper part of the follicle (the isthmus and infundibulum), and this includes the bulge, where the stem cells are. Once this part is destroyed, the whole follicle is replaced by fibrous tissue, that is, scar tissue, and the hair loss at that site can no longer be reversed. Even when the patches look similar on the surface, the outlook and the treatment strategy diverge depending on whether the stem cells remain or have been destroyed.

How They Differ to the Naked Eye and Under Dermoscopy

The Typical Look of Alopecia Areata

• Bald patches that appear suddenly, coin-shaped and with sharp borders
• Scalp color is normal or slightly pink
• Follicular openings (pores) remain visible, with no shiny scarring
• In the acute phase, exclamation mark hairs at the edge of the patch
• In most cases neither itchy nor painful
• In some people, small pinpoint dents in the fingernails or toenails (nail pitting) can accompany it

What Scarring Alopecias Have in Common

Across the scarring alopecias, what is seen in common is loss of the follicular openings (follicular ostia) and shiny scar tissue. In the active phase, the inflammatory findings specific to each condition, listed in the table above, are added to this.

Under Scalp Dermoscopy

On scalp dermoscopy (also called trichoscopy), the key point in alopecia areata is that the follicular openings are still there. The openings remain visible, and yellow dots, black dots, exclamation mark hairs and short, fine hairs coming through are often seen with them. In effect, what we are seeing are follicles getting ready to grow hair.

In scarring alopecia, the key point is that the follicular openings appear to have gone. The skin in the area of hair loss is smooth and shiny with hardly any openings visible, and a red band, scaling, crusts, tufted hairs and pustules may be seen around it. Even without going as far as a biopsy, the dermoscopy findings alone are often enough to point us in a direction.

Three Things We Look at First in Clinic

• Whether the follicular openings are visible or gone — if the openings are visible, we think first of non-scarring hair loss, and within that of alopecia areata. If no openings are visible and the area looks like a smooth, shiny scar, we suspect scarring alopecia.
• Whether there are skin symptoms — in alopecia areata there is usually little or no pain or itching, and the skin is fairly calm. Scarring alopecia often comes with itching, stinging, pain and a burning sensation, and a red band, scaling, crusts and pustules are commonly seen along with it.
• How it is progressing — in alopecia areata, the round bald area tends to fill in with treatment or time as fine hairs come through. In scarring alopecia, the area widens in a jagged shape while the center becomes steadily smoother and shinier, and the edge stays red and sensitive for a long time.

These three alone are enough to point us in a direction: whether this is hair loss that can grow back, or hair loss that needs to be stopped quickly, even now. They are criteria that point us in a direction, though, so when it is unclear we confirm with dermoscopy and a biopsy.

The Order in Which the Diagnosis Is Narrowed Down

1. Check the pattern of hair loss — we look at whether it is localized, with a few round patches, or diffuse, with thinning all over, and whether or not it follows a pattern, such as the crown or an M-shaped hairline.
2. Check for scarring — we check the follicular openings with dermoscopy. If they are visible, it is non-scarring and we consider the possibility of alopecia areata; if they have gone, we lean toward scarring alopecia.
3. Estimate the specific condition from characteristic findings — yellow dots, black dots and exclamation mark hairs point toward alopecia areata; scale and redness around the follicles toward lichen planopilaris; follicular keratin plugs and branching, tree-like vessels toward discoid lupus erythematosus; lesions centered on the crown and a halo around the hairs (peripilar halo) toward central centrifugal cicatricial alopecia; and pustules, tufted hairs and honey-colored crusts toward folliculitis decalvans.

Some cases are still unclear after these three steps. In that case we take a biopsy from the edge where inflammation is ongoing, that is, the active margin, for final confirmation.

When Are a Biopsy and Blood Tests Needed?

Most cases can be diagnosed from the clinical findings and dermoscopy, but a biopsy is considered in the following situations.

• When findings of alopecia areata and scarring alopecia are mixed, so the two cannot be clearly told apart from appearance and dermoscopy alone
• When scarring alopecia is strongly suspected and separating the conditions, for example lichen planopilaris from discoid lupus erythematosus, matters for the choice of treatment
• When hair loss has been progressing for years and the diagnosis is not clear
• When the condition is already fairly advanced and we need to confirm whether it is still progressing or has stopped

A biopsy can provide information that decides the direction of treatment, such as whether it is indeed alopecia areata, whether it belongs to the lichen planopilaris group, or whether it is a lupus-type scarring alopecia. In Korea, scalp biopsies are mostly carried out at university hospitals that have a pathology department.

Differences Seen in the Tissue

Lichen planopilaris shows a lichenoid lymphocytic infiltrate hugging the upper follicle, loss of the sebaceous glands and arrector pili muscles, and fibrosis around the follicle. Discoid lupus erythematosus shows interface dermatitis in the upper part of the follicle, follicular keratin plugs and thickening of the basement membrane. In folliculitis decalvans, a neutrophilic infiltrate dilates the follicle, and as it progresses this leads to follicular rupture, mixed inflammation and scarring.

The Role of Blood Tests in Alopecia Areata

For the diagnosis of alopecia areata itself, the scalp findings and dermoscopy are often enough. Blood tests are less about finding the cause of the hair loss than about checking for associated conditions and overall health. Depending on the situation, we selectively consider basic blood tests, liver and kidney function, thyroid function tests (TSH, T3, T4 and others), nutritional status such as iron and ferritin, and, where needed, autoantibodies (such as ANA) and vitamin D.

Not every patient with alopecia areata needs extensive testing, and we adjust the scope according to age, symptoms, medical history and associated conditions. There can be limits to the tests available at a local clinic, so when a detailed evaluation is needed, further tests are sometimes carried out at a university hospital.

The Same Steroid Injection, but a Different Goal

Intralesional steroid injections, given directly into the area of hair loss, are used in both conditions. On the surface they look like the same injection, but where they are placed and what they are for differ.

Alopecia Areata — An Injection to Help Hair Grow Back

For limited patches (the patchy type), intralesional steroid injection is one of the commonly used first-line treatments. It is placed evenly across the whole patch at 1 cm intervals to reduce inflammation around the follicles and help regrowth. This is because the follicle's stem cells are alive, leaving room for hair to grow back once the inflammation settles.

Scarring Alopecia — An Injection to Stop Further Loss

In scarring alopecia, the principle is to inject only the active margin, where redness and scaling are visible. The aim is to suppress the inflammation so that the surrounding follicles are not destroyed any further. Injecting the scarred center that has already turned smooth and shiny does not bring follicles back.

If a scarred area is taken for alopecia areata and injected in the same spot again and again for months, the expected effect may not come, and skin atrophy, indentation or pigment changes may be all that is left. This is why diagnosis comes before starting injections. The skin atrophy that can follow intralesional steroid injection is also explained in our article on keloids and hypertrophic scars.

How the Direction of Treatment Differs

What follows is a general explanation of how the two conditions are treated. The actual medication, dose and duration are decided after an examination, according to the diagnosis and your condition.

Alopecia Areata — Hair Loss That Often Recurs but Can Grow Back

First-line treatment for limited lesions is intralesional corticosteroid injection (triamcinolone acetonide) and application of a potent topical steroid (such as clobetasol). When the condition is severe or extensive, systemic steroids and topical immunotherapy (DPCP, SADBE and others) are used.

As of November 2025, JAK inhibitors such as baricitinib, ritlecitinib and deuruxolitinib are being used as a new option for severe alopecia areata. Some people show clear improvement, but relapse is common when the drug is stopped, so a characteristic of this treatment is that a maintenance strategy is needed. Whether each drug is approved varies by country and over time.

Scarring Alopecia — Three Shared Directions

What matters in treating scarring alopecia is less the name of the condition than the shared goal: not reviving follicles that have already been destroyed, but protecting the follicles that remain.

• Settle the inflammation quickly and fully — topical steroid creams and lotions, intralesional steroid injections limited to the active margin, and immunomodulators such as hydroxychloroquine, methotrexate, ciclosporin (cyclosporine) and mycophenolate are used.
• Keep it settled for a long time — tetracycline antibiotics such as doxycycline and minocycline are often used as maintenance therapy for months to years in lichen planopilaris, frontal fibrosing alopecia, folliculitis decalvans and other conditions.
• Reduce added irritation to the scalp — avoid hairstyles that pull too tightly and strong heat or chemical treatments, protect the scalp from UV, and avoid harsh shampoos and scrubs.

Why Antibiotics Are Used When There Is No Infection

Tetracycline antibiotics are drugs often used in scarring alopecia, especially in lichen planopilaris and folliculitis decalvans. They are often used for their anti-inflammatory effect rather than because there is a bacterial infection. Because they regulate inflammation itself through mechanisms such as inhibiting tissue-destroying enzymes (MMPs), inhibiting the formation of new blood vessels, antioxidant action and suppressing the production of inflammatory cytokines, they can be used at a low dose as long-term maintenance therapy even in inflammatory conditions without infection.

In scarring alopecia, the purpose of oral medication is not to make hair grow but to put out the inflammation that destroys follicles. These are drugs that need long-term use and monitoring for side effects, so they should not be taken on your own initiative the way an ordinary hair loss medication might be; an accurate diagnosis, a choice of drug that fits the condition and regular tests have to go together.

When Hair Transplantation Can Be Considered

In scarring alopecia, hair transplantation is an option weighed at the final stage. It can be considered only after it has been confirmed that there has been almost no inflammation for at least 1–2 years and that the area of hair loss is no longer widening. This is because rushing while inflammation remains can mean the transplanted hair also falls out again and the scarring worsens.

So at the stage when a transplant is being considered, a biopsy is sometimes used to confirm whether the inflammation is currently active or has already passed, leaving only scarring. ABLE Dermatology does not perform hair transplantation.

Outlook, and Signs That Call for a Second Look

The Outlook in Alopecia Areata

There are reports that mild, limited (patchy) alopecia areata recovers on its own within 1 year in a fair number of cases. On the other hand, some cases can progress to extensive forms that spread to the whole scalp or the whole body (alopecia totalis, alopecia universalis). The outlook tends to be less favorable when onset is at a young age, when the lesions are extensive or follow an ophiasis pattern, or when there are nail changes, a family history or an accompanying autoimmune disease.

The Outlook in Scarring Alopecia

Left untreated, scarring alopecia progresses little by little but steadily, and at some point reaches a "burned-out" state in which the inflammation has died down. At that stage there may appear to be no inflammation, but the follicles at that site are already gone. That is why, in scarring alopecia, the outlook depends on how early it is suspected and how quickly the inflammation is brought under control.

We think about recovery in two parts. In areas already replaced by scar tissue, the follicles have been destroyed and recovery is difficult. The follicles that still remain can be protected, and further progression prevented, if the inflammation is suppressed quickly and fully. The difference in outcome between cases found early and treated actively and cases where treatment began after time had passed can be large.

Have It Checked Again in These Situations

• When you were told it was alopecia areata but, after months of treatment, it does not feel as if it is improving
• When the area of hair loss is becoming smoother and shinier and the follicular openings no longer seem to be visible
• When an itchy, stinging area of hair loss seems to keep widening

If you notice any of these signs, a differential diagnosis that includes an examination by a board-certified dermatologist, scalp dermoscopy and, where needed, a biopsy may help. This article is a general explanation and does not replace an individual diagnosis.