Traction alopecia: how to avoid tight hairstyles and protect your edges

Last updated 2026-07-09

TL;DR

Traction alopecia is hair loss from repeated tension on the follicle, most often from tight braids, ponytails, weaves, and locs. The American Academy of Dermatology says catching it early is the difference between full regrowth and permanent scarring. Loosen your styles, rotate them, and give your edges rest weeks between installs. Once the scalp turns smooth and shiny, the follicle is usually gone.

What is traction alopecia and why does it hit edges first?

Traction alopecia is hair loss from long-term mechanical tension on the follicle. The pulling damages the follicle wall over time, disrupts the growth cycle, and, if the stress runs long enough, scars the follicle so hair cannot grow back at all. [1]

Edges go first for a simple reason. The hairs along your hairline are finer, and their follicles sit shallower than the ones on your crown. Less tissue holds them down. So when you pull a tight ponytail or press a stiff lace front onto those short, fine hairs, they take more relative force than anything else on your scalp. The AAD names the hairline, temples, and nape as the zones most open to traction damage. [1]

The condition was first described in detail in 1907, among Greenlandic women who wore their hair in tight buns. Research over the last two decades shows it lands disproportionately on Black women, because of the cultural and social pressure around smooth, pulled-back styling. A 2016 review in the Journal of the American Academy of Dermatology put prevalence at roughly 17 percent of Black women in population-based studies, with some clinic samples closer to 31 to 33 percent. [2] The spread comes from how each study recruited people. Nobody has a clean national number yet.

Here is the point that changes everything you do next. In early traction alopecia, the follicle is inflamed but still alive. Stop the tension and hair can come back. Wait until the scalp looks smooth and shiny at the temples, with no visible follicle openings, and you have crossed into scarring territory where regrowth is unlikely even with treatment. [1]

Which hairstyles does the AAD say to avoid?

The AAD's patient guidance flags a specific set of high-tension styles. The message is not to quit protective styling. It is to change how those styles get installed and worn. [1]

High-tension styles the AAD calls out:

  • Tight braids, cornrows, and box braids, especially pulled toward the hairline
  • Tight ponytails, buns, and topknots
  • Dreadlocks, particularly in the early locking phase, when the root gets retwisted tight over and over
  • Weaves and extensions sewn onto braided cornrows, which pile tension at the braid base
  • Tight headbands worn every day
  • Roller sets or pin curls kept in overnight and pulled taut

The AAD is direct that adding extensions raises both the weight and the pull at the follicle past what your own hair would ever create. [1] Synthetic hair weighs more than human hair at the same length, which matters a lot if you like waist-length box braids. A 2019 study in the International Journal of Dermatology found traction alopecia patients were much more likely to have worn extensions for over five years and to have started tight styles before age 18. [3]

The pattern of loss tells you a lot. Traction alopecia almost always tracks the line where the style pulls hardest: a receding band along the frontal hairline from temple to temple, sometimes with a spared "fringe" of hairs too short to get caught, plus thinning at the nape where bun elastics sit. [1]

For a fuller look at traction alopecia symptoms, stages, and treatment, that article covers the clinical picture in full.

How tight is too tight? Understanding tension thresholds

Here is where honesty matters, because no one has published a clean peer-reviewed tension number in newtons or pounds and said "past this, your follicle dies." Follicle biology is not that tidy. What the research gives us instead are useful proxies.

Pain is the clearest one. If a fresh style causes scalp pain, a headache along the temples, or small bumps at the hairline in the first 24 to 48 hours, the tension is already high enough to cause inflammation. The AAD says a style should never hurt when it goes in. [1] Sounds obvious. But plenty of stylists treat pain as proof the braids are neat and built to last. They are right that tighter braids last longer. They are wrong that the trade is worth it.

A 2021 paper in Skin Appendage Disorders found that follicular papules, those small pimples at braid bases, are an early histological warning sign of traction damage. See them show up after every install, and your follicle is already cycling through inflammation. [4]

Folded earlobes are an old, practical test too. If the braids along your sides pull tight enough to fold your ears forward, the tension at your hairline follicles is high. No study measures this exactly. It is the kind of thing dermatologists notice in the room.

For kids, the AAD is blunter. Avoid tight protective styles in children before puberty whenever you can, because young follicles are not fully anchored yet and take permanent damage from tension an adult could shrug off for a while. [1]

Traction alopecia prevalence by study sample type | Percentage of Black women affected, by how study participants were recruited
Population-based studies 17%
Clinic-based samples (dermatology) 31%
Clinic-based samples (highest reported) 33%

Source: Khumalo NP et al., Journal of the American Academy of Dermatology, 2016 [2]

What does early vs. late traction alopecia look like?

Knowing your stage shapes every decision that follows.

Stage What you see Follicle status Regrowth possible?
Early (inflammatory) Scalp redness, follicular papules, mild recession, edges look thin after takedown Inflamed but intact Yes, once tension stops
Intermediate Visible hairline recession, baby hairs gone, no papules anymore, some scalp smoothness Partial follicle damage Partial, with intervention
Late (scarring) Smooth, shiny scalp at temples, no follicle openings visible, recession stable for years Follicle destroyed Unlikely without surgery [5]

The smooth, shiny scalp at the temples is the sign that stops dermatologists short. By then the follicle has been replaced by fibrous scar tissue. A biopsy in late-stage traction alopecia shows what pathologists call "replacement of follicular structures by fibrous tracts," the same process seen in other scarring alopecias like lichen planopilaris. [5]

Most women who write about this online first notice the thinning right after taking down a long-term style. That takedown window is the best moment to look at your edges honestly, with no product on the scalp, in good light. If the hairline reads thinner than before the style went in, take it seriously now, before you re-install.

For more on what healthy edges hair looks like and how to check your own hairline, that article walks through the anatomy and the warning signs.

How can you prevent traction alopecia while still wearing protective styles?

Protective styles really are protective when they are done right. The goal is never zero braids or zero ponytails. The goal is less total tension over time. Here is what the evidence and clinical guidance actually back. [1][3]

Install looser at the hairline. The inside of a style can run fairly snug for longevity, but the first inch of hair around the perimeter needs a lighter hand. Tell your stylist plainly to leave the hairline braids looser than the rest. A good one will not take it as an insult.

Take breaks between installs. The common clinical recommendation is to rest your hair at least two to four weeks between back-to-back protective styles. In that window your scalp recovers, inflammation settles, and you get to see whether the last style caused any new recession. [1]

Limit how long a style stays in. Even a loose install turns into a tension source as your roots grow out, because the braid or extension base tightens against the scalp. Most dermatologists suggest pulling braids and weaves within six to eight weeks. Push to twelve or sixteen weeks with no touch-up and cumulative tension climbs fast. [1]

Skip heavy extensions on thinning edges. If your temples already show recession, hanging long, heavy extensions off those exact follicles is the worst possible move. Shorter, lighter extensions, or none at all along the perimeter, cut the mechanical load in a way you can feel.

Do not stack tension sources. A tight headband over a tight ponytail is two loads on the same follicles. A satin-lined bonnet or satin pillowcase drops overnight friction and lets you skip the tight style while you sleep.

Use flexible ties, never rubber bands. Rubber bands and metal elastics bite into the shaft and make one focal point for breakage. Spiral coils and fabric-covered ties spread the pressure over more surface. [1]

For a full breakdown of which protective hairstyles are genuinely low-tension and which need modifying, that guide covers install details by style type.

Can you reverse traction alopecia or regrow thinning edges?

In the early and intermediate stages, yes, there is real regrowth potential once you remove the tension source. The AAD states plainly that "if caught early, traction alopecia is reversible." [1] The key word is early.

What the research supports for early recovery:

Remove the tension first. Nothing else works without it. No oil, no supplement, no topical fixes a follicle that gets pulled every single day.

Minoxidil (Rogaine) has the most evidence for waking up follicles that went dormant from traction. It is FDA-approved for androgenetic alopecia and used off-label by dermatologists for traction alopecia. No large randomized trial exists for minoxidil and traction alopecia specifically. The closest data come from case series and expert opinion. [6]

Scalp massage raises blood flow to the follicle. A 2016 study in ePlasty found standardized scalp massage, four minutes daily for 24 weeks, increased hair thickness in men with androgenetic alopecia. [7] Whether that carries straight over to traction recovery is unproven, but the risk is near zero and the mechanism (better follicular circulation) is plausible.

Rosemary oil has early evidence as a topical growth support. A 2015 randomized controlled trial in SKINmed compared rosemary oil to 2% minoxidil and found comparable hair count gains at six months, with fewer scalp side effects. [8] That trial studied androgenetic alopecia, not traction, so treat the crossover as honest hedging. It is still the best controlled data we have. If you want to try a topical, rosemary oil for hair growth is a sane starting point before you spend money on pricier options.

If you are fighting overlapping causes, like postpartum shedding on top of existing traction damage, recovery drags out. Postpartum hair loss runs on a completely different hormonal mechanism and resolves on its own schedule. Read about it separately so you are not blending the two and chasing the wrong fix.

In late-stage scarring traction alopecia, the options narrow hard. Hair transplant surgery (follicular unit extraction into healthy donor areas) is the only thing that restores hair to a scarred scalp, and outcomes ride on how much scarring there is. Platelet-rich plasma (PRP) injections get used by some dermatologists, but the evidence for scarring alopecia specifically is thin. [6]

Edge Naturale's natural hair growth collection is built around rosemary, castor oil, and biotin-rich botanicals, aimed at women in early recovery who want to support their scalp while keeping styling gentler. It is not a treatment for scarring alopecia and the brand makes no such claim. For early-stage edge thinning where the follicle is still alive, supporting scalp health while you rest from tight styles is a sensible move. Browse the natural hair growth products page for options that slot into a lower-tension routine.

What do dermatologists actually recommend for treating traction alopecia?

The AAD's treatment recommendations follow a stepwise logic: remove the cause first, then support recovery. [1] Here is how a board-certified dermatologist usually works through a new traction alopecia patient.

First visit: rule out other causes. Traction alopecia can look like frontal fibrosing alopecia (FFA) or lupus-related hair loss. A dermatologist may take a scalp biopsy to confirm the diagnosis before building a plan. This matters. FFA needs different treatment, and treating traction alopecia with style changes alone while an autoimmune cause hides underneath would delay real care. Traction alopecia and FFA can look clinically identical, and biopsy is what tells them apart. [10]

Styling counseling. The dermatologist gives specific instructions on which styles to drop, often in writing. The AAD publishes printable patient materials for exactly this. [1]

Topical anti-inflammatories. In the inflammatory early phase, a topical corticosteroid (clobetasol or betamethasone) on the scalp can calm inflammation around the follicle and improve regrowth odds. It is prescription-only. No over-the-counter product does the same thing.

Minoxidil. Usually the 5% foam once daily, if the dermatologist thinks the follicle still has growth capacity. Results take four to six months to judge.

Injections. Intralesional corticosteroid injections into the scalp can cut inflammation in stubborn cases. They are uncomfortable and not first-line for traction alopecia.

Surgical referral. If a patient has been stable, no further recession, for at least one to two years and has a good donor area, a hair transplant consult becomes worth having. Operating before the disease is stable risks losing the grafts to ongoing traction.

The honest reality is grim on timing. Many women reach a dermatologist too late, after years of tight styling already scarred the scalp, because the early signs are subtle and get normalized. The AAD's guidance keeps coming back to the same lever: public education about early signs is the strongest tool for preventing permanent loss. [1]

Are some women more at risk for traction alopecia than others?

Yes, and the risk factors cluster in ways worth knowing.

Race and hair texture. Traction alopecia is far more common in Black women than in any other group. The 2016 review in the Journal of the American Academy of Dermatology found 17 percent prevalence in Black women in population studies, against much lower rates elsewhere. [2] This is not about anything built into the follicle itself. It is about styling traditions and social pressure that treat tight, smooth-edged looks as professional and polished.

Age of first tight styling. Starting tight styles in childhood raises lifetime risk a lot. The 2019 International Journal of Dermatology study found patients who wore tight braids before age 18 had a statistically higher risk of traction alopecia by their 30s. [3] Pre-pubescent follicles are not fully anchored.

Duration of styling. The same 2019 study found that wearing extensions for more than five cumulative years raised risk significantly. [3] This is cumulative damage, not a one-style problem.

Other hair loss conditions. Women who already have androgenetic alopecia or thyroid-related thinning start with less follicular reserve. The same tension a healthy follicle handles briefly can push an already-stressed one past its limit.

Occupation and sport. Gymnasts, ballerinas, competitive swimmers in daily tight caps, and military women in regulation buns show raised traction alopecia rates in clinical case reports. This is a styling problem, not a cultural one.

Genetics. There seems to be individual variation in how tightly follicles anchor, though no specific gene is pinned down. Some women wear tight styles for decades with no visible recession. Others develop it in a few years. Nobody has good data on why, yet.

What ingredients and scalp care habits actually support edge recovery?

Once the styling changes are in place, scalp care can support the environment a follicle needs to try to recover. The evidence runs from solid (minoxidil, corticosteroids) to promising-but-early (rosemary oil, castor oil, scalp massage) to mostly folklore (most viral edge-growth recipes). Being straight about that spread helps more than pretending everything works the same.

Ingredients with real evidence:

Rosemary oil (1 to 2% dilution in a carrier). The 2015 SKINmed randomized trial found hair count gains comparable to 2% minoxidil at six months. [8] Use it diluted as a scalp oil, not full strength, and massage it in instead of just dabbing it on. To make your own, how to make rosemary oil for hair walks through a clean method.

Castor oil. No human randomized trial exists for hair loss specifically. What we have is mechanistic work suggesting ricinoleic acid is anti-inflammatory. Many women report better texture and scalp moisture. It is thick and stubborn to wash out, so keep it light at the scalp.

Peppermint oil. A 2014 Korean study in Toxicological Research found 3% peppermint oil in jojoba oil beat minoxidil on hair count in mice, with a proposed mechanism of more dermal thickness and more follicles. [9] The jump from mice to human use is a real gap, and this has not been replicated in human trials, but the risk is low at proper dilution. Read more about essential oils for natural hair growth that carry at least some mechanistic support.

Gentle cleansing. A clean scalp lets follicles work and lowers the risk of folliculitis (scalp infection) that can pile onto traction damage. Wash your scalp every one to two weeks at minimum, even under protective styles, with a sulfate-free shampoo taken straight to the scalp and rinsed all the way out.

Ditch alcohol-heavy edge control. High-alcohol pomades and gels used daily on thinning edges dry out the shaft and the scalp. If you use edge control, look for water-based formulas with no isopropyl alcohol in the first five ingredients. Smooth edges should never cost you a dried-out scalp.

Hairline breakage sometimes gets mistaken for traction alopecia, since both make edges look thin. The difference is where it happens. Breakage is a shaft problem (the hair snaps off above the scalp). Traction alopecia is a follicle problem (the hair stops growing from the root). Hair breakage causes and prevention are worth reading if you are not sure which one you have.

How do you talk to your stylist about traction alopecia risks?

This is the conversation most women dread, and it is the one that changes the most.

The trouble is that a lot of salon culture treats pain and tightness as proof of good work. A style that lasts is a style that feels tight. Stylists trained this way are not out to hurt you. They learned a technique that produces the look clients ask for. Shifting it takes clients being specific about what they want and why.

Say what you need before the stylist starts. Something like: "I'm dealing with thinning at my temples, so I need the edges left looser than the rest of the braids. I know the style may not last as long, and that's fine with me." That frames it as a health issue, not a knock on their skill.

Ask about extension weight up front. Getting braids with synthetic hair? Ask the brand and type. Lightweight options like Kanekalon exist precisely because heavy extensions cause traction, and many experienced natural hair stylists already switched.

Bring a photo of the tension level you want at the hairline, more than the finished style. Stylists work visually. Showing them soft, loose edges along the perimeter reads better than describing it.

If a style hurts when it is done, say so right then. You have the right to ask them to redo the perimeter. The soreness that creeps in a day later is harder to fix, so before you leave the chair, ask them to loosen any braid that feels uncomfortably tight.

If your stylist insists tight is the only way, that is your cue to find someone who specializes in natural hair and has worked with traction alopecia clients. Dermatologists can sometimes recommend stylists, and the AAD has a "find a dermatologist" tool if you want a physician referral first. [1]

What does the AAD specifically say about traction alopecia prevention?

The AAD's public guidance on traction alopecia is one of the clearest plain-language summaries you can get from a credentialed medical body. It is worth quoting directly, because it gets paraphrased badly all over the internet.

The AAD states: "To prevent traction alopecia, dermatologists recommend that their patients: Wear loose hairstyles when possible, as tight hairstyles put more tension on the hair and scalp. Avoid hairstyles that put constant tension on the hair. If you frequently wear your hair in a style that pulls, try to choose a style that requires less tension." [1]

The AAD also says: "If you feel pain or notice small pimples along your scalp, change your hairstyle or see a board-certified dermatologist." [1] That instruction to see a dermatologist, not only to change your hair, is the part most social media advice drops.

Other prevention points the AAD states directly [1]:

  • Do not use chemicals (relaxers, perms) and tight styles at the same time, because chemically processed hair is weaker and gives out under tension sooner
  • Use conditioning treatments to keep hair supple, because brittle hair breaks at lower tension loads
  • If you notice recession or thinning, do not wait to see if it clears; see a dermatologist, because early traction alopecia responds far better than late-stage disease

The NIH's MedlinePlus page on hair loss also lists traction as a recognized, preventable cause and points patients toward dermatologists for early evaluation. [6]

No major dermatology group has published a minimum "safe" number of hours per day for tight styles, because the evidence does not support a precise threshold. The AAD's guidance is directional: less tension, more rotation, stop if it hurts.

Frequently asked questions

Does the AAD say tight braids cause traction alopecia?

Yes. The American Academy of Dermatology specifically lists tight braids, cornrows, ponytails, and weaves as styles that can cause traction alopecia by putting repeated mechanical tension on the follicle. Its guidance says to wear these styles loosely and take breaks between installs. If you feel pain or see scalp papules after a style goes in, the AAD recommends seeing a board-certified dermatologist.

Can traction alopecia grow back?

In the early inflammatory stage, yes. The AAD states traction alopecia is reversible if caught early. Once the scalp shows smooth, shiny skin with no visible follicle openings, the damage has likely become permanent scarring, and regrowth without surgery is unlikely. Early-stage recovery after tension stops usually takes three to twelve months, though results vary a lot by person and by how long the tension lasted.

How long should I rest my hair between protective styles?

Dermatologists generally recommend at least two to four weeks between back-to-back tight protective styles. That window lets scalp inflammation settle and lets you check whether the last style caused new recession. Wearing protective styles back-to-back with no breaks gives your follicles zero recovery time, and the cumulative tension compounds over months and years.

What does traction alopecia look like at the early stage?

Early traction alopecia usually shows as a thin band of recession along the frontal hairline, often temple to temple, sometimes with small pimples or bumps at the braid or ponytail base. Baby hairs start disappearing. The scalp is still slightly textured and follicle openings are visible. This is the stage where stopping the tension and seeing a dermatologist makes the biggest difference for regrowth.

Is traction alopecia the same as a receding hairline?

Not exactly, though they look alike. Traction alopecia comes from mechanical tension and follows the line where the pull is highest, usually the frontal and temple hairline. Androgenetic alopecia (genetic hair loss) also causes recession, but it follows a different pattern and is driven by hormones, not styling. A dermatologist can tell them apart, sometimes with a biopsy, and the treatments differ meaningfully.

Can children get traction alopecia from tight braids?

Yes, and the AAD notes children's follicles are more vulnerable because they are not fully anchored in the scalp. Research in the International Journal of Dermatology found that starting tight braiding before age 18 significantly raises the risk of traction alopecia in adulthood. Dermatologists generally recommend avoiding tight styles in young children entirely and keeping any protective styling loose.

Do relaxers make traction alopecia worse?

Yes. The AAD explicitly warns against combining chemical services (relaxers, perms, color) with tight styles. Chemically processed hair is structurally weaker and breaks at lower tension than natural hair. Using a relaxer and then installing tight braids or weaves puts already-compromised hair under stress it is even less equipped to handle. If you relax, your edges need especially loose styles and more frequent rest periods.

What is the best edge care routine for thinning from traction?

Stop the tight styles first. Nothing else works without that step. After that: gentle cleansing every one to two weeks, a lightweight scalp oil with rosemary or peppermint oil in a carrier (worked in with a massaging motion), and no alcohol-heavy edge control on the thinning area. See a dermatologist for prescription options like topical corticosteroids or minoxidil if two to three months of self-care shows no improvement.

How many Black women are affected by traction alopecia?

A 2016 review in the Journal of the American Academy of Dermatology estimated traction alopecia affects about 17 percent of Black women in population-based studies. Clinic-based samples have found rates as high as 31 to 33 percent among Black women seeking dermatology care. The wide range reflects differences in how and where participants were sampled, not errors. No nationally representative US prevalence study exists yet.

Can tight ponytails cause hair loss even without extensions?

Yes. The AAD lists tight ponytails and buns as causes of traction alopecia independent of extensions. Extensions add weight and total tension, but a very tight daily ponytail worn over months or years creates enough repetitive force to inflame and eventually scar follicles along the hairline and nape. Switching to looser ponytails, fabric-covered elastics, and varying the ponytail position day to day cuts cumulative tension.

How do I know if my edges are breaking or falling out from the root?

Look at the shed hair under good light. A white bulb at one end means it shed from the root (a telogen shed hair). Ragged, split, or tapered ends with no bulb mean it broke off above the scalp. Traction alopecia is true follicle damage, so you will see the hairline getting shorter over time, more than thin and wispy at the ends. Breakage shortens the hair you have; traction alopecia stops new growth.

Does wearing a wig every day cause traction alopecia?

It depends on the install method. Wigs worn with no adhesive or clips, sitting loosely on your natural hair, add little tension. Wigs glued to the hairline with strong adhesive, or clipped in tight enough to pull the perimeter hair, can cause the same follicle damage as any other traction source. Lace front wigs applied with bonding glue daily have been linked to frontal hairline traction alopecia in clinical case reports.

Should I see a dermatologist or try home remedies first?

If you notice any hairline recession, see a dermatologist before committing months to home remedies. The window for reversible traction alopecia is time-sensitive. Spend six months oiling what is actually scarring alopecia and you have lost six months of treatment. Home care with rosemary oil, scalp massage, and gentle styling can run alongside a dermatology visit; they are not mutually exclusive. A biopsy can tell you definitively which stage you are in.

What is the AAD's recommendation for hairstyles that are safer for edges?

The AAD recommends loose braids and twists, styles that keep tension off the hairline, wigs and toppers worn without tight attachment, and loose low buns with fabric elastics. It advises rotating styles so no single part of the scalp carries tension continuously, and loosening or removing tight styles at night. The overarching principle: a style should be painless from install through takedown.

Sources

  1. American Academy of Dermatology (AAD), Traction Alopecia: How to prevent it: AAD recommendations on hairstyles that cause traction alopecia, early warning signs, and dermatologist guidance to wear loose styles and stop if pain or papules occur
  2. Khumalo NP et al., Journal of the American Academy of Dermatology, 2016; prevalence of traction alopecia: Traction alopecia prevalence estimated at approximately 17 percent of Black women in population-based studies, up to 31-33 percent in clinic samples
  3. Ogunleye TA et al., International Journal of Dermatology, 2019; risk factors for traction alopecia: Wearing extensions for more than five years and starting tight braids before age 18 significantly increased traction alopecia risk
  4. Pulickal JK et al., Skin Appendage Disorders, 2021; follicular papules as early histological marker: Follicular papules at braid bases are an early histological warning sign of traction damage to the follicle
  5. Miteva M, Tosti A, American Journal of Dermatopathology, 2012; biopsy findings in late traction alopecia: Late-stage traction alopecia biopsy shows replacement of follicular structures by fibrous tracts, consistent with scarring alopecia
  6. MedlinePlus (NIH National Library of Medicine), Hair Loss: Traction is a recognized, preventable cause of hair loss, and minoxidil is used for follicle stimulation; patients directed to dermatologists for early evaluation
  7. Koyama T et al., ePlasty, 2016; standardized scalp massage and hair thickness: Four minutes of daily scalp massage for 24 weeks increased hair thickness in men with androgenetic alopecia
  8. Panahi Y et al., SKINmed, 2015; rosemary oil vs. minoxidil 2% RCT: Rosemary oil produced comparable hair count improvement to 2% minoxidil at six months with fewer scalp side effects in a randomized controlled trial
  9. Oh JY et al., Toxicological Research, 2014; peppermint oil and hair growth in mice: 3% peppermint oil in jojoba oil outperformed minoxidil for hair count in a mouse model, with proposed mechanism of increased dermal thickness and follicle number
  10. Samrao A et al., British Journal of Dermatology, 2011; frontal fibrosing alopecia vs. traction alopecia differential diagnosis: Traction alopecia and frontal fibrosing alopecia can appear clinically similar; biopsy distinguishes them and guides different treatment protocols