Though seborrheic dermatitis does not cause hair loss directly, it can result in damage, microinflamttion, and blockage of the hair folliciles and this can lead to hair loss .
To put things into perspective, a two day survey comparing the hair-loss rate between dandruff affected invididuals and unaffected controls showed that those affected by dandruff shed 100-300 hairs, while the control group only shed 50-100 . This would impply that those affectd by dandruff are seeing 1x-6x the rate of hair loss.
Blockage Causes More Brittle Hair
Blockage of the hair folicicle is the result of dead skin (the flakes) clogging the entrance way. This can cause abnormal production of sebum and new hair growth, as seen Pityrosporum folliculitis [3, 4]. The end result, is hair that is noticabley thinner and weaker.
Gentle removal of skin flakes can be helpful to reduce blockage, but the most significant relief will come from succesful management of seborrheic dermatitis itself.
Direct Damage is the Resut of Itching
Much of the direct damage to the hair follicle is actually the result of excessive itching and physical pressure/friction (as you scratch the seborrheic dermatitis affectedskin) . Though this affect can be minimized by enforcing exceptional self-control (not scratching the skin), it is easier said then done. If you’ve ever exeperienced seborrheic dermatitis, you know how difficult it can be to resist the itch; once the skin starts acting up, it’s nearly impossible.
Additional Aspects to Consider
While blockage and damage of the hair follicles are two primary causes of the hair loss seen in seborrheic dermatitis, there are several other components that may need to be considered.
- Stress, Depression, And Anxiety
Facing a skin condition such as seborrheic dermatitis usually has a significant impact on your well-being and can be a source of significant stress, depression, and anxiety. These metnal states can in-turn induce hormonal changes in the body that may negatively impact the hairs natural growth cycle. This is a possible reason why telogen effluvium often accompanies seborrheic dermatitis .
Some seborrheic dermatitis treatments may hepful for primary symptoms, but may be counter-productive to maintaining optimal hair growth. For example, the commonly used antifungal agent selenium sulfide has been seen to cause alopecia (hair loss) in some users .
Underlying Health Issues
Individuals with compromised immune function are noted to have a higher chance of being affected by seborrheic dermatitis. These same underlying issues may also be imperative to healthy hair growth.
If left untreated, the symptoms of seborrheic dermatitis can lead to excessive hair loss and a reduce rate of new hair growth. Though the hair loss itself is not considered a primary symptom of seborrheic dermatitis, it can be viewed as a side-effect of the symptoms of seborrheic dermatitis.