Author: Dr. William Rassman

How do they know that Sebhoraic Dermititus and Psoriosis do not cause hair loss? You wrote on your blog once that it can cause reversible hair loss indirectly by the inflammation accelerating telogen effluvium. Can the inflammation in someone that does not have telogen effluvium do this? Many (not all) of my outer brows fall out by just touching them gently. I have sebhoraic dermititus, is this accelerated a normal symptom of the condition or does this mean I also might have telogen effluvium?

• Seborrheic dermatitis causes scaly, itchy, red skin and dandruff. It is a skin condition. It is not a hair condition.
• Telogen effluvium is diffuse hair shedding which is triggered by some form of stress that makes the hair go into the shedding (telogen) cycle. Hairs usually grow back in 6 to 12 months.

I suppose any inflammation or trauma or stress can cause hair loss, but these types of hair loss are generally reversible and do not occur in everyone… just some susceptible people. I suppose extreme seborrheic dermatitis can trigger telogen effluvium, but it would be rare. It may cause some hair loss from scratching producing traction alopecia (not as drastic as telogen effluvium).

(female)
Dr. Rassman, thank you for time. I have read your answer as well as several other sites that state ‘A’ CT scan is not sufficient to cause hair loss. I have been having repeated intensive CT scans. My research has shown that the amount per CT scan (chest, abdomen and pelvis) is relative to approximately 1/4 the radiation exposure of a survivor of the atomic bombs that were set off in Japan. I have now had 8 such scans in a year and a half period. There are more issues than hair loss that drove me to my doctors seeking answers, but they have none for me. The only other significant health or living circumstance change for me in this time period has been weight loss. I ask you again because my question is so specific to the amount of radiation I am receiving… Is it possible repeated CT scans (versus ‘a’) could cause hair loss?

Certainly it is possible that radiation from multiple computed tomography (CT) scans of the scalp could produce hair loss. Various CT scanners produce varying amounts of radiation but even your 6 CT scans to the head may not be enough radiation to produce hair loss like victims of the atomic bomb experienced. There is not much information available to produce a more certain answer to your question.

Hi doctor.

I recently asked you a question regarding if testosterone rise from propecia can cause hair loss, you said that testosterone doesn’t cause hair loss but DHT does. Someone else asked you if receiving testosterone shots can cause hair loss you replied:

“First of all I do not know why you are receiving testosterone shots. I would discuss all its negative side effects (including hair loss, liver damage, etc) with your doctor.

If you have the gene for androgenic balding, testosterone will increase the balding rate and possibly even continue on if you stop the testosterone therapy. If you do not have the balding gene, your hair should be safe with increasing amounts of testosterone, but your body may decay.”

Now here you clearly state testosterone does cause hairloss: “testosterone will increase the balding rate “

if someone takes propecia it means they have the balding gene, so then propecia will decrease DHT and in return increase testosterone that will lead to more hairloss. Please clarify this if you can because it is really confusing. I would really appreciate it. Thank you! you have an awesome blog! keep up the good work

Testosterone is metabolized by the body into DHT. If you increase your testosterone, your body will metabolize the testosterone and make more DHT as a byproduct of the metabolic process. It is the DHT that causes hair loss (if you have the genes for it).