Suddenly, out of the blue, your hair starts falling out, maybe by the fistful. It could be telogen effluvium — temporary hair loss often caused by prolonged, intense stress, an infection or physical trauma, such as from a car accident or surgery.
“It occurs after a person has undergone a stressful life event that shocks the body, such as battling a virus,” said Dr. Alissa O’Brien, a board-certified dermatologist with Water’s Edge Dermatology.
COVID-19 appears to have triggered a rash of new cases, whether from the infection, the treatment (including being on a ventilator), emotional stress related to the pandemic or some combination.
Dr. O’Brien said the new cases aren’t surprising, since post-infection hair loss is a well-known phenomenon. “Approximately three months after a ‘stressful’ event, the hair sheds much more than normal. Up to 50% of the hair can be temporarily lost due to telogen effluvium.”
While emotional stress can trigger hair shedding, “in my experience, the worst cases usually follow major physical stressors, such as infection with COVID-19, ICU hospitalization, being on a ventilator or temporary dialysis,” said Dr. O’Brien.
Certain medical conditions, such as liver, kidney and thyroid disease, and some medicines can also trigger telogen effluvium, as can extreme weight loss from crash dieting. Mild telogen effluvium is common after pregnancy.
How the hair loss happens
Hair naturally goes through periods of growing and shedding. At any given time, 85 percent of your hair is in the growth (anagen) phase; the remaining 15 percent is in the resting (telogen) phase. After about three months in the telogen phase, hair falls out.
When a stressor or trauma disrupts this cycle, many of the hairs that were in the growth phase abruptly enter the resting phase. Three months later, the hair becomes thinner — sometimes dramatically so.
“Up to 70% of the hairs that were in the anagen phase may be affected. It can seem like your hair is coming out in handfuls,” said Dr. O’Brien. The hair loss can come as shock. “Looking in the mirror can be quite distressing when you notice up to half your hair has fallen out,” Dr. O’Brien added.
People experiencing telogen effluvium may also develop horizontal indentations in the fingernails and toenails known as Beau’s lines.
Telogen effluvium treatment
The good news is that telogen effluvium is temporary. Hair will grow back, though it may not fill in completely, and the strands may be thinner. Unfortunately, there’s no way to speed this process along.
“Many patients want a magic pill, shampoo, serum or vitamin to take, but the only treatment is time,” said Dr. O’Brien. “The hair will return to its normal growth and resting cycle, but it takes anywhere from six to 12 months to fully recover.”
For people with severe hair loss, that span can feel like eternity. Hair extensions or hair pieces can bridge the gap.
Watching your hair fall out may be demoralizing, but unlike with certain other types of hair loss, if you have telogen effluvium, you’ll eventually notice new strands coming in on their own — and see that reassuring head of hair in the mirror again.
Article Written By: Jessica Brown, a health and science writer/editor based in Brooklyn, New York. Her work has appeared in Prevention, Johnson & Johnson, the Breast Cancer Research Foundation, and many more.