Scarring alopecia is an umbrella name for a number of hair loss problems that affect around 3% of all people who experience hair loss. It has the alternate name cicatricial alopecia and occurs in both males and females of any age, all over the globe.
While scarring alopecia is the general name for a number of specific conditions, these are rarely diagnosed independently. There are many such diseases, the most common being folliculitis decalvans, lichen planopilaris, pseudopelade of Brocq, dissecting cellulitis, eosinophilic pustular folliculitis or the hot comb alopecia, also known as the follicular degeneration syndrome. Sometimes, the cause is chronic lupus erythematosus, a more general disease that affects many areas of the body.
While there are many specific diseases, they all have in common the same symptoms. Regardless of the cause, the end result is the permanent destruction of hair follicles, while scar tissue develops in the area.
In most situations, scarring alopecia starts with limited areas of baldness that grow slowly in time. The evolution of the condition is variable. It sometimes expands very fast and causes redness, itching or even pain. However, it can also progress very slowly, without any associated symptoms, and only becomes visible after a long time.
The areas affected by scarring alopecia look a little bit different from the ones of alopecia areata. However, on closer inspection, the edges of scarring alopecia patches are more irregular. Sometimes, hair loss is the only visible symptom because the actual destruction of the hair follicles happens under the skin. The patches might become red or covered with scales. In some cases, the color of the skin changes or the scalp is covered with wounds or blisters of pus emerging from under the skin. The skin can also be smooth, without any obvious issues.
Scarring alopecia is not easy to diagnose using just the external appearance, even if the visible symptoms can provide valuable clues. Biopsies are often requested by doctors in suspected cases of scarring alopecia in order to confirm the diagnostic and try to find the real cause. In some cases, more than one biopsy is needed. Microscope examination of a tiny biopsy with a diameter of no more than 4 mm is usually performed. Doctors investigate the presence of scar tissues under the skin, the destruction of hair follicles or the presence of inflamed areas close to the hair follicles.
Sometimes, the first sign of scarring alopecia is inflammation surrounding the hair follicles. Some scientists suspect that inflammatory cells cause the destruction of the follicles and their replacement with scar tissue. Other dermatologists don't agree with this hypothesis. They argue that in some cases biopsies of people with scarring alopecia don't reveal any inflammation at all.
In almost all cases, scarring alopecia eventually stops expanding. All of the related symptoms like itching or inflammation disappear and the areas without hair stop growing. If a new biopsy is performed at this stage, no more inflammation is present but the bald areas no longer have any active hair follicles. The edges of the bald patch can sometimes have a number of damaged follicles that are still alive and will eventually recover. The destroyed follicles are replaced with deep scars that mark their former location in the skin.
The disease must be carefully monitored at all times, even during treatment or after its completion. Scarring alopecia might not react well to treatment or can appear again at the end of a period of medication. The disappearance of external symptoms such as itching or inflammation is usually a sign that the treatment is working properly. Other visible signs include the healing of pustules, absence of redness or scaling, as well as a noticeable decrease in the expansion of bald patches and hair loss rate. Dermatologists use these external signs to monitor the progression of scarring alopecia. A modern method that helps following the effectiveness of treatment is to make pictures of the scalp and compare them.
Scientists don't understand well the mechanism behind scarring alopecia. All forms of the disease appear to include the inflammation of the top areas of the hair follicles. This is where both the sebum gland and the stem cells of the hair are found. Their destruction makes the regrowth of the follicle absolutely impossible and the result is permanent hair loss without any chance of recovery.
In most cases, scarring alopecia does not appear to be linked with any other disease and can't be transmitted to other people. It often affects healthy males or females who don't have other problems.
Both sexes can develop the disease at any age, but adults normally have a much higher risk. Scarring alopecia is a poorly understood condition and no real epidemiologic studies have been made in order to provide more information about it. It is difficult to predict because it tends to be rare and doesn't seem to be affected by genetic factors. However, central centrifugal cicatricial alopecia is a type of the condition that affects women from the same family and is a lot more common among females with African heritage. Scarring alopecia is not connected with other conditions that cause hair loss and none of them can evolve into it.