Not everything I see in the Emergency Department is an emergency, but that doesn’t make it any less interesting. Consider the lady in her 30s who came in to report that she was sure her hair was suddenly falling out. She had noted increased hairs in her shower drain and in her hair brush this week and was quite concerned that she would end up bald.
She knew this was likely an irrational fear, but she was upfront in reporting it and wanted my opinion.
I carefully looked over her luxuriant head of hair and even tugged on a lock of it. A few hairs came out when I tugged. Was that normal? Was she going bald? She gave me a curious look.
The lifespan of any single human hair varies depending on where it is on the body. In a healthy person with good genes a scalp hair can continue growing for as long as eight years before finally dying and being replaced. The life span of eyebrow hair is three months, while body hair is even shorter-lived at about one month.
At any given point 90 percent of our hair follicles are in the growth phase (anagen phase), which, as noted, can last many years. Ten percent of our hair follicles are in the resting or telogen phase, which comes after the anagen phase. In the telogen phase the hair stays in the scalp for three months and then is shed. It is normal to lose 50 to 150 hairs a day in this cycle. The cycle is asynchronous, thus you don’t normally have mass shedding of hair and regrowth at any one time but rather continuous low level shedding.
But you can occasionally have a spontaneous mass shedding of hairs under certain conditions of stress, illness, injury or hormonal changes. This is called telogen effluvium. The mechanism of telogen effluvium is not completely understood, but it seems that some physiologic stressors disrupt the anagen phase and throw up to 35 percent of growing hair follicles into the telogen phase. They then shed en masse three months after the illness or injury. Almost all reported cases are in women.
I tugged at another lock of her hair and counted the number of hairs between my fingers; fifteen. Definitely abnormal; in this “hair pull test” we do, normal is less than five hairs shed. Fifteen hairs are virtually diagnostic of telogen effluvium, but what was the cause?
I delved into her history a little more. Specifically I wanted to know what had happened to her three months ago to send so many of her hair follicles from the anagen (growth phase) to the telogen (resting) phase all at once.
She had not delivered a baby, a somewhat common cause of telogen effluvium, nor had she had a major injury, which can also cause it. She did have hypothyroidism, which can cause hair loss, but recent thyroid hormone levels were normal, so that was unlikely to be the cause.
While we were talking, I took her hands in mine and carefully inspected them. This was one of the first diagnostic maneuvers I learned in medical school from a wise old mentor. It builds trust. The very act of reaching out and holding another’s hands is both therapeutic and can be diagnostic.
In this case I noted faintly indented lines running perpendicularly across her nails. Beau’s lines!
First described in 1846 by a French physician, Beau’s lines are a response to acute illness or injury. Essentially the nail stops growing for a period of time in response to physiologic stress on the body and then resumes growth once the illness has passed. To some extent the severity and the length of the illness can be estimated by the depth and width, respectively, of the Beau’s lines.
I had a hunch about what had caused her telogen effluvium and Beau’s lines.
I asked this nice lady if she had received the Covid vaccine. She had not. She thought she had had Covid about three months ago, a self-diagnosis she had made after an exposure and a subsequent fever. I think she was probably right. Her hair was falling out three months after a fever put many of her hair follicles into telogen. The viral illness was most likely Covid.
This was not really a brilliant insight on my part; nearly everything in the ER these days is Covid.
I assured my patient that her hair loss was self-limited and she wasn’t going to become bald. Most telogen effluvium is mild and results in modest hair loss and little cosmetic effect. The hair shedding and fingernail deformities would resolve over the next six months without any treatment. Of course, I encouraged her to get vaccinated against Covid (for her hair and nails if nothing else).
She said she would think about it. I am sure the hair clogging her drain every morning will be a good reminder.
P.S.: It is time to get your flu shot. Nobody wants the flu.