Scarring Alopecia and Shedding Hair: Is Shedding Increased?

Is Shedding Increased?

Hair shedding is normal. Everyday humans lose hair from the scalp. For people who shampoo their hair every other day, typical shedding would involve 20-60 hairs on a non wash day and 40-140 on a shampooing day. These of course are averages and there is quite a bit of variation in these numbers across the population. People who shampoo daily notice less hairs and people who shampoo once weekly notice more hairs.

Increased hair shedding is said to occur when the individual feels they are losing more than they normally would lose. 
There are a variety of causes of increased hair shedding including telogen effluvium, chronic telogen effluvium, androgenetic alopecia, scarring alopecia and alopecia areata. 
Increased hair shedding is commonly seen in scarring alopecia. Hairs don’t grow particularly well with inflammation in the scalp and are triggered to shed. In contrast to telogen effluvium where only telogen hairs are shed, patients with scarring alopecia can shed telogen hairs (resting hairs) and anagen hairs (actively growing hairs). Shedding is important to recognize and document when evaluating a patient with scarring alopecia. This is especially true in follow up appointments after a treatment is started. For example, a patient with active lichen planopilaris who reports they once shed alot of hair every day and now after 4 months of hydroxychloroquine feels they are shedding less hair may be providing evidence that the treatment is helping. Of course, other information such as changes in scalp symptoms (itching, burning, pain) is also important to ascertain since reduction in symptoms may also indicate possible success of treatment. 
The prototypical hair shedding condition is telogen effluvium but that does not mean that all patients who report increased shedding have a diagnosis of telogen effluvium. Many different and distinct hair loss conditions are associated with increased daily shedding. Reduction in shedding for any type of condition generally signals the condition is improving to some degree.

Hair shedding is important to evaluate and monitor in all types of hair loss including scarring alopecia.