Do I need a scalp biopsy if I have scarring alopecia?
Question:
I have been diagnosed with frontal fibrosing alopecia, which I understand to be a type of scarring alopecia. My dermatologist wants to start me on treatment right away. Do I need a biopsy first?
Answer
Dermatologists have many different views as to whether every patient with potential scarring alopecia needs a scalp biopsy or not. These views fall in three main categories:
1) There are some dermatologists who believe that every single patient with hair loss (scarring or non-scarring) gets a biopsy.
2) There are some dermatologists who conduct a scalp biopsy in every single patient with scarring alopecia.
3) There are some dermatologists who perform a biopsy if the diagnosis is not certain and there is even the slightest ambiguity in the diagnosis.
I fall in the third category. My decision on whether a patient needs a biopsy comes during the final steps of a typical patient evaluation. First (step 1), I listen to the patient’s story about their hair loss (we call this a history). Second (step 2), I examine the scalp using a dermatoscope. Third (step 3) I review blood tests. Fourth, I decide whether a biopsy is needed given all the information I have collected during steps 1-3. If the diagnosis is clear and there simply can’t be another diagnosis possible, I don’t do a biopsy.
Here’s an example. Suppose a 56 year old female patient comes to see me. She started losing her eyebrows at age 51. At age 54 she started losing hair along her frontal hairline and it’s receded now about 1⁄2 inch. She’s lost her arm hair, pubic hair and leg hair. Examination shows a scarring alopecia along the frontal hairline. Her blood tests are normal. Based on steps 1-3 I’m confident in the diagnosis of a condition known as frontal fibrosing alopecia.
Will I do a biopsy? No. I will not recommend doing a biopsy in this situation. If the biopsy returns showing scarring alopecia, it’s true that I will have confirmed the diagnosis. Not a bad thing of course. But I will have caused the patient an unnecessary scar. Also, there is always the potential that biopsies (or any trauma) can further activate scarring alopecias, so I’d like to stay away from that.
But suppose the biopsy returns showing something else – such as androgenetic alopecia or alopecia areata. Biopsies are not 100 % accurate so once in a while a scenario like this does occur. In a situation like this, I won’t believe the biopsy results. I’ll simply put the biopsy results aside and move on with discussing treatment. In other words, I’d simply have to explain to the patient that biopsies are not perfect. The reality is that I have caused an unnecessary scar. There may also have been unnecessary expense for getting the biopsy done. There may have even been some pain and discomfort for a few days.
Suppose in the above example, we change things a bit. Suppose the patient is a 56 year old female patient like in the above example. She started losing her eyebrows at age 51. At age 54 she started losing hair along her frontal hairline and it’s receded now about 1⁄2 inch. She’s lost her arm hair, pubic hair and leg hair. She has joint pain in her wrists and ankles, unusual rashes, extreme fatigue and prominent lymph nodes enlarged in her neck. She is troubled by headaches and has had 2 seizures this year that nobody can figure out why. She has dry mouth and dry eyes. Examination shows a scarring alopecia along the frontal hairline. Her blood tests are abnormal with low white cells, abnormal kidney function tests, as elevated liver enzymes. Her ANA is borderline positive at 1:160. When I examine her scalp, I have the impression this is a scarring alopecia – resembling very close frontal fibrosing alopecia.
Here’s a good example of where I will do a scalp biopsy. Even though it seems the patient has frontal fibrosing alopecia, I want to rule out other conditions such as cutaneous lupus, discoid lupus, lymphomas, various infiltrative conditions, including some rare cancers.
You may wish to review these helpful articles (below) I've written in the past. Thanks again for the question.