Provider Practice Essentials registered nurse continuing education

Post-COVID 19 Hair Loss

Kelsey Bates, APRN

What we have witnessed over the last years with the COVID-19 pandemic has been gut wrenching. It’s rough enough to have the coronavirus! Post-viral problems can make things even worse. One particular post-COVID issue I’d like to focus on is telogen effluvium, or post-Covid 19 hair loss.

Post-Covid Hair Loss

What is telogen effluvium?

Teleogen effluvium is a form of nonscarring, typically acute, hair shedding. The hair shedding is diffuse and excessive.

Let’s look at a normal scalp first:

There are two forms of hair, anagen hair and telogen hair. Anagen hair is actively growing hair and makes up about 85% of the scalp. Telogen hair is resting hair, making up 15% of the scalp. There is a short transition period between the anagen and telogen hair phase, known as the catagen hair phase. Catagen hair lasts for 10-20 days before it is considered telogen hair. Hair is usually in the actively growing phase (anagen) for four years and in the resting (telogen) phase for four months. Likewise, there is a usual pattern or hair growth followed by rest.

Now let’s look at telogen effluvium:

Hair shedding occurs after a physiologic trigger. About 70% of the anagen hair abruptly transitions to telogen hair. The hair rests for an average of three months and then reenters the growth phase. Upon reentry of the growth phase the hair that was resting begins to extrude. Hair shedding then becomes apparent to the individual. Telogen effluvium does not discriminate against gender, race or age. Women are more likely than men to report (and be bothered by) hair shedding. This is what we see with post-COVID 19 hair loss.

Potential triggers for telogen effluvium:

  • Acute febrile illness
  • Severe infection
  • Major surgery
  • Severe trauma
  • Physical and emotional stress
  • Postpartum hormonal changes (decrease in estrogen)
  • Hypothyroidism
  • Crash dieting, low protein intake
  • Micronutrient/nutritional deficiencies (Vit D, Vit B12, iron)
  • Heavy metal ingestion
  • Medications (beta blockers, retinoids, anticoagulants, propylthiouracil, carbamazepine, and immunizations)

Making the diagnosis

The majority of the time, subjective and objective information will also lead to the diagnosis. It is important to collect a detailed history and go back in time to ask the patient about potential physiologic triggers. The trigger has usually occurred three months prior to the hair shedding but can range between one to six months prior. If this is your first time seeing the patient, it also may not be evident that any hair shedding has occurred. It may be helpful if the patient has a picture of themselves prior to the hair shedding for you to see a comparison. Close examination of the scalp will also reveal short anagen hairs growing in.

Hair Pull Test

The acute shedding phase Is the best time to perform this test. A test is considered positive if the patient loses four or more hairs after a gentle hair pull. However, the pull test may be unreliable if the patient has washed their hair within 24 hours of the test being performed.


Trichoscopy is also a useful diagnostic test. The frontal and occipital locations, and also the area above the ears should be studied. The visualization of hair is helpful for the provider and also the patient.

Scalp Biopsy

A scalp biopsy can also confirm the diagnosis. It may also not be necessary. The decision to perform a biopsy should be based on the subjective and objective findings previously discussed.

Serial Hair Collection

Serial hair collection should be performed if the patient declines scalp biopsy. The patient should collect all hair shedding in a 24-hour time period. Likewise, this should be done weekly for three to four weeks. Patients should also avoid hair washing during the 24-hour collection period. Serial hair collection testing is considered positive if 100 or more hairs are collected in a 24-hour time frame.

Underlying Disease Investigation

Many medical conditions can cause also hair loss. Endocrine and hematologic causes for hair loss should also be considered. Diet should also be discussed and reviewed, along with the medication profile. If an underlying condition is found, it should be treated first. Identifying and treating the trigger is vital for the resolution of telogen effluvium.

Patient education and management

The good news for post-COVID 19 hair loss and related cases…the hair shedding is not permanent. For the patient, however, telogen effluvium can be devastating to experience. To a patient, “hair shedding” feels more like “hair loss.” Put yourself in the patients’ shoes, if you woke up tomorrow and had A LOT of hair come out compared to your normal, wouldn’t that worry you? It would definitely worry me. It may make it easier on patients if we can help them view it as “hair shedding” versus “hair loss.”

Stressing over the hair shedding has the potential to make the shedding worse because the individual is enduring more emotional stress. These individuals need reassurance that this is not a permanent situation and their hair will return to its normal state with time, on average six months but can last up to twelve months. If the patient is really having a hard time emotionally with the hair shedding, also consider getting them into counseling for extra support.

There is no medication that has proven beneficial for this condition. Topical agents are usually not helpful. Educate patients that it is safe to continue washing and also styling their hair as normal, this will not affect the hair shedding either way. Also, make sure to reassure them. that this air loss is temporary!


Hughes E.C. & Saleh D. Telogen Effluvium. [Updated 2021 Jun 8]. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Available from:

Ocampo-Garza, S. S., Vastarella, M., Nappa, P., Cantelli, M., & Fabbrocini, G. (2021). Telogen effluvium in the new SARS-CoV-2 era. International Journal of Dermatology, 60(7), 265-266.

Rebora A. (2019). Telogen effluvium: a comprehensive review. Clinical, Cosmetic and Investigational dermatology, 12, 583–590.

Learn more about this and other dermatology topics with our Practice Essentials in Dermatology.

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