‘Significant hair shedding’: Japanese dermatologists link hair loss to COVID-induced ‘cytokine storm’

In a letter to the Journal of Dermatology​, a team of dermatologists from Hamamatsu University School of Medicine and the Fujinomiya City General Hospital said it is likely that various hair loss symptoms will emerge following the outbreak of COVID-19.

“As the COVID-19 pandemic continues, more patients may experience several types of hair loss. Careful observation of each hair loss symptom and appropriate diagnosis and treatment selection are important.​

The researchers reported a case of post-COVID-19 spot balding and excessive hair shedding in a 47-year-old woman.

Three weeks after the patient was discharged from the hospital, where she was treated for high fever and severe pneumonia induced by COVID-19, she experienced alopecia areata (AA), also known as spot baldness.

The researchers hypothesised that hair loss could be attributed to the “overzealous cytokine production”​ associated with the COVID-19 illness.

“This cytokine storm can lead to other disorders, including several autoimmune diseases.​ IFN-α and IFN-γ are also crucial inducers of AA after viral infections… ​Of course, there is no direct way to prove that COVID-19 is the cause of AA, but IFN-γ dominant intracytoplasmic cytokine balance may indicate COVID-19-induced AA in our case.”​

The researchers concluded: “In our case, the COVID-19-induced cytokine storm may have caused not only high fever and severe pneumonia but also a sudden switch from the anagen to the catagen phase, followed by the telogen phase.”​

A curious case of hair loss

This case of COVID-induced hair loss was not an isolated case. The researchers pointed out that there have been several case reports of the new onset of AA one to two months after the onset of COVID-19.

The patient was treated for AA, but as soon as it improved, the patient also experienced significant hair shedding – losing more than 200 hairs a day – and was diagnosed with telogen effluvium (TE) 13 weeks after her COVID-19 infection.

Under dermoscopic observation, it was revealed many vellus hairs on the scalp. Vellus hair is characterised as thin and wispy hair, sometimes known colloquially as baby hair.

The team performed a hair-plucking test and found that telogen hair accounted for about 40% on the scalp.

There are four stages of the hair growth cycle: anagen, catagen, telogen and exogen. Telogen hairs are at a stage of resting and remain in their follicles without actively growing.

“​Our patient also suffered from acute TE, which is characterised by significant hair shedding that lasts less than six months and results from an abrupt shift in the hair cycle from the anagen phase to the catagen phase and subsequent entry into the telogen phase,”​ elaborated the researchers.

After eight weeks, terminal hair regrowth was observed, and the excessive shedding had “almost completely stopped”,​ according to the letter.

A case of telogen effluvium followed by alopecia areata after SARS-CoV-2 infection​

Kageyama et al.

Source: Journal of Dermatology​

DOI: 10.1111/1346-8138.16590​