The Bigger Picture Must Not be Forgotten When Diagnosing Hair Loss
Emily Carr was a Canadian artist and became well know for her landscape paintings - especially of trees and the forest.I like this quote of Emily Carr. It reminds us to always consider the meaning of the the “bigger picture.”
The use of techniques like trichoscopy have really changed how physicians practice hair loss medicine. Seeing the scalp up close increases accuracy to diagnose certains hair loss conditions. But we must always remember to step back and consider the “bigger picture.”
For example, although physicians come to learn that hair follicle “miniaturization” is a feature of androgenetic alopecia (male and female balding), the finding of a small number of miniaturized hairs on the scalp does not necessarily mean that much. The advice about seeing the “bigger picture” is useful for patients too. The occasional thin hair a patient sees in the brush should not necessarily cause alarm. At least not with taken the entire scalp density into context.
Emily Carr’s words are indeed wise .... “In the forest think of the forest, not this tree and that.”
The examples for the scalp could go on and on., The finding of one hair with so called “perifollicular scale” around the hair does not necessarily mean the diagnosis is the scarring alopecia lichen planopilaris if the surrounding areas of the scalp still look normal.
And on we go. The finding of a single scar on the scalp does not necessarily mean scarring alopecia. A single twisted hair does not necessarily mean the “pili torti” of scarring alopecia. A single pustule does not mean much either.
Just like a forested area may have tens of thousands of trees (or more) depending on whether one is referring to a local neighbourhood forest or the forests of the deep wilderness, the scalp itself has up to 100,000-120,000 hairs. If a patient is suspected to have hormonal issue or immune based issue or genetic issue as the cause of their hair loss but yet only seems to have changes affecting one or two hairs when the scalp is examined we need to at least consider the possibility that we’re not quite barking up the right tree (as the expression goes). Perhaps we don’t quite have the diagnosis.
It’s certainly true that many hair diseases favour certain areas of the scalp and leave other areas unaffected. So, we might not expect all the hairs to be affected. In addition, every disease has to start somewhere so one could argue that at least one hair up there on the scalp needs to be the very first hair affected in any given disease. The reality is that even when we diagnose diseases in the very earliest of stages, we generally see many hairs affected - not just one
The area that genetic hair loss affects may contain 25,000-40,000 hairs. By the time we’re confidently able to diagnose genetic hair loss clinically some 10-20 % of hairs in a given area are showing “miniaturization.” In other words many thousands of hairs on the scalp show the key diagnostic features. The area that frontal fibrosing alopecia affects may contain 5000 - 10000 hairs. Certainly more than one hair is likely to be affected by the patient’s activated immune system. Similarly the immune system in patients with lichen planopilaris may be patrolling an area containing 30,000-70,000 hairs depending on the extent. A single finding in one hair follicle does not carry much significance. After all, why would the immune system target one hair and not disturb thousands (or tens of thousands) of others nearby?
While the tools we have in trichoscopy are wonderful and have changed how hair dermatology is practiced, we need to always consider the bigger picture. Emily Carr’s quote is a nice reminder that we need to step back and consider what is happening on a bigger scale to hundreds of hairs in an area - of better yet - to tens of thousands of hairs in the area.
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887