Scarring alopecia is hair loss that is accompanied by destruction of the hair follicles. Although no scars are visible to the naked eye, the once intact follicle has changed into a tiny connective tissue scar, which experts can clearly distinguish from an intact hairless follicle. Hair can no longer grow from destroyed, scarred hair follicles – so hair loss due to scarring alopecia is irreversible.
What is Scarring Alopecia?
Scarring alopecia is not associated with diffuse hair loss, but also not with a typical pattern of hair loss as in androgenetic alopecia. Instead, hair loss almost always starts at one or more small, clearly defined but arbitrarily localised areas where the hair is largely completely lost. If the disease is not treated, these areas grow, can fuse together and ultimately occupy larger areas of the scalp.
The destruction of the follicles is the end point of an inflammatory process in which the body’s immune system turns against the hair follicles. If the diagnosis is made in time, there is a chance to stop the inflammation and to bring the disease under control, although not to heal it.
A distinction is made between primary scarring alopecia, in which the inflammation is directed against the healthy hair follicles without any recognisable external trigger. Less mysterious are secondary scarring alopecia, where the inflammatory process has a clearly recognizable external trigger. Here, the hair follicles are to a certain extent collateral damage in a defence process that is originally directed against a microbial infection by fungi, bacteria or viruses or against tissue in the vicinity of the hair follicles that has been destroyed by burns, injuries, radiation, skin tumours or other damaging influences.
But beware: Scarring alopecia are not always as easy to classify as they appear to be. Scarring alopecia of the primary type can be triggered by external influences: Reactions to drugs, allergens or relatively harmless microorganisms can, if predisposed, become the starting point of an excessive immune reaction that is ultimately directed against the body’s own tissue. In addition, those affected sometimes have mixed forms or combinations of different diseases.
The most important triggers of primary scarring alopecia are the autoimmune diseases Lichen ruber planopilaris and lupus erythematosus. A special form of alopecia is the traction alopecia caused by permanent pulling on the hair roots by particularly tightly coiffed hair. This can also lead to loss of hair follicles in the late stages. The most frequent of the secondary scarring alopecias is tinea capitis, which is caused by fungal infections.
Lichen ruber planopilaris
As a subform of the nodular lichen (Lichen ruber planus), which attacks the skin, mucous membranes and nails, Lichen ruber planopilaris manifests itself exclusively on the scalp. The frequency of lichen ruber planopilaris is only known to be significantly lower than that of lichen ruber planus (about one percent of the population is affected). The disease belongs to the rare diseases (orphan diseases) . It is not an infectious disease: the term “lichen” is misleading – there is no exogenous pathogen involved. Lichen ruber is not contagious.
Lichen ruber planopilaris occurs preferentially between the ages of 40 and 60 and somewhat more frequently in women; very rarely has the disease been described in childhood. There are no known family clusters, so there is no evidence of heredity of the disease.
Symptoms and diagnosis
The affected persons present themselves to the dermatologist with hair loss and in places inflamed scalp. Already bald areas are smooth and pale and no longer show follicle openings. If the disease is active, they are surrounded by an inflamed zone with reddened skin, the follicles of which have a clearly keratinized “wreath”. Sometimes the affected areas are itchy or painful, but often there are no accompanying symptoms. Dermatologists diagnose the active disease on the basis of a scalp biopsy. A subtype of Lichen ruber planopilaris is frontal fibrosing alopecia, which progresses from the forehead area and usually also affects the eyebrows, possibly the eyelashes .
Lichen ruber planopilaris is not curable. Treatment with anti-inflammatory drugs aims at suppressing the symptoms and slowing down hair loss. It must be initiated in the early stages of the disease if possible, is time-consuming and can be frustrating; failures and relapses after treatment stops are frequent.
The treatment is handled differently by different specialists. In general, however, treatment is initially with local and later with systemically applied glucocorticoids (cortisone & co.). There are also experiences (partly limited to single case reports) with the systemic application of cyclosporine, mycophenolate-mofetil, hydroxychloroquine, tetracycline, doxycycline or methotrexate and with the local application of tacrolimus. These drugs intervene at different sites in an inhibitory way in the inflammatory process .
Minoxidil can stimulate the growth of the remaining hair and thus improve the appearance.
Frontal fibrosing alopecia is a special case that generally responds particularly poorly to the usual treatments with anti-inflammatory drugs. Here, some encouraging successes have been achieved in recent years with finasteride in off-label use  The doctors reporting these therapeutic successes suspected that post-menopausal women suffering from frontal fibrosing alopecia may have a mixed form with androgenetic alopecia in which the inflammatory reaction was directed directly against the hair follicles altered by androgenetic alopecia.
In most cases, the disease ends as spontaneously as it began. It is not possible to predict when this will happen and how extensive the hair loss that has occurred up to that point will be.
Hair transplantation can be considered for hair loss due to Lichen ruber planopilaris. However, in order to minimise the risk of failure, special care should be taken in this case. The prerequisite is at least six months of inactivity of the disease and an inconspicuous current biopsy result. Since surgical interventions can trigger a new flare-up of the disease, a “test balloon” should be started first: For this purpose, hair is transplanted only in a small area, the development of which is observed for six to twelve months. If the success of the test transplant is assured and the absence of inflammatory symptoms continues, a comprehensive transplantation can be started with good prospects.
Lupus erythematosus is usually not a pure skin disease, but shows a variety of symptoms and often unpredictable progressions, in which inflammatory processes can be directed not only against skin and hair follicles, but also against joints and internal organs. One speaks of cutaneous lupus erythematosus (lupus of the skin) when a systemic lupus shows skin symptoms or when only skin symptoms occur. Skin lupus is often accompanied by scalp involvement and scarring alopecia. The most common form of cutaneous lupus is discoid lupus erythematosus. Here, the inflammatory processes occurring in the form of localised foci (disks = slices, spots) affect only the skin .
Lupus erythematosus is very rare (estimated at about 0.01%), occurs predominantly between the ages of 20 and 40 (women are more frequently affected) and, as can be concluded from the familial accumulation of cases, it certainly has an inherited component. Discoid lupus erythematosus as a sub-form of the disease is correspondingly still somewhat rarer.
Symptoms and diagnosis
Symptoms of discoid lupus erythematosus are inflammatory skin lesions that appear in the form of irregularly shaped but sharply defined, slightly swollen red to purple scaly patches mainly on light-exposed areas of skin on the face, earlobes, scalp and neck. If the disease progresses, the individual patches may grow and then present as light scar tissue surrounded by a darker ring of active inflammation. Furthermore, the rash may also appear on other parts of the body. Itching, burning or pain do not usually occur in connection with lupus skin changes, but areas of active inflammation show increased sensitivity to touch.
Lupus diseases are chronic and often progress in phases. Without treatment, the end point of local inflammation of the skin in discoid lupus is scar tissue, which usually differs from healthy skin by underpigmentation (conspicuous paleness) and atrophy (contracted, sunken skin). If untreated, lupus lesions of the scalp usually lead to scarring alopecia, i.e. permanent loss of hair in the affected area. With timely and consistent treatment, hair loss can often be avoided.
Due to the overlap with other skin diseases, the diagnosis of discoid or general cutaneous lupus can hardly be reliably established on the basis of the skin condition. A skin biopsy and/or a blood test for certain typical antibodies usually provides certainty.
The skin rash in discoid lupus is treated locally with ointments containing various active ingredients that inhibit the immune system. These are first of all glucocorticoids (fluocinonide, hydrocortisone), in second line the so-called calcineurin inhibitors (tacrolimus, pimecrolimus). If many and extensive lesions occur, systemic drugs (mostly initially hydroxychloroquine) are used  This therapy shows efficacy in about 75 % of the patients. Severe cases with a high tendency to relapse can additionally be treated with immunomodulating agents (e.g. acitretin, methotrexate and thalidomide), which are successfully used in other autoimmune diseases. However, systematic studies on the effectiveness of these drugs in skin lupus are largely lacking .
UV light is one of the most important triggers for lupus symptoms. Therefore, highly effective sun protection or avoidance of the sun is an essential part of managing the disease.
Hair transplantation can also be promising for hair loss due to skin lupus. The prerequisite is that the disease is inactive or very well under control. At first, a trial transplantation should be carried out, the development of which is observed for a few months. If the hairless area has not expanded further and the hair transplanted in the test procedure grows successfully, the prospects for a regular transplantation to cover the entire affected area are favourable.
Traction alopecia is hair loss that is caused by constant pulling on the hair roots.
The pulling forces can be exerted by very tightly coiffed ponytails or topknots/dutts, by tight braided hairstyles with many small braids or cornrows, by dreadlocks as well as by hair extensions (weaves and extensions). If these forces have a long-term effect, i.e. if the corresponding hairstyle is worn daily or around the clock, the risk of traction alopecia is relatively high: according to dermatologists, for example, a third of African American women who wear cornrows or dreadlocks suffer from this form of hair loss.  The risk increases if the hair has also been chemically straightened or otherwise treated. Naomi Campbell is one of the prominent sufferers – it is said that the extensions were possibly to blame .
Symptoms and diagnosis
Traction alopecia occurs at the points where the greatest traction forces act. Typical is the hair loss at the hairline caused by ponytail or hair knots. Dreadlocks and cornrows can cause a pattern of bald patches on the entire scalp.
The diagnosis is not always easy – confusion with female androgenetic alopecia, alopecia areata or other forms of scarring alopecia is possible. Sometimes the receding hairline leaves a thin, frayed hairline intact at the level of the original hairline – this is considered typical of traction alopecia. Experienced dermatologists also diagnose traction alopecia using the combined information from trichogram and scalp biopsy. Frequently, the so-called hair cylinders (pseudonits, tube scales), which are easily visible to the naked eye, also occur – these are special scales in the form of small tubes “strung” on the individual hairs .
The constant mechanical irritation leads to an inflammation of the hair follicles. This inflammation can be stopped at an early stage: by immediately giving up the “guilty” hairstyle and by local, possibly also systemic anti-inflammatory treatment, including glucocorticoids (cortisone and related active ingredients). Even with successful treatment, the regrowth of new hair can take months to years.
In some published individual cases, good experience has been made with minoxidil: For example, a 2% minoxidil solution finally brought the desired success to two women who had previously waited in vain for more than a year for new hair growth after six and nine months of regular use, respectively .
In the later stages of untreated tractionalopecia, the follicles are irreversibly destroyed. However, affected persons are good candidates for hair transplantation.
Tinea capitis: Fungal infections of the scalp
Tinea capitis is the medical name for an infection of the scalp with skin fungi (dermatophytes). The disease, also known as “ringworm of the scalp”, occurs quite frequently in children, rarely in adults, but there are no representative surveys on the frequency.
Tinea capitis can be caused by different fungal species and is highly contagious in any case. The pathogens are often transmitted by animals, especially Microsporum canis (cats, especially in Southern Europe) and Trichophyton menthagrophytes (guinea pigs) are known. Trichophyton tonsurans and Microsporum audouinii preferentially infect humans, the transmission occurs from person to person.
Symptoms and diagnosis
Tinea capitis leads to one or more clearly defined hairless areas on the head. The scalp there is either completely hairless and densely covered with mealy scales, or it is severely reddened, with pus blisters, incrustations and thinning hair. Remaining hair can be easily pulled out. If the infection reaches deep into the lower layers of the skin (tinea capitus profunda), the inflammatory reaction is particularly pronounced. Itching can, but need not, occur.
Experienced dermatologists make the suspected diagnosis on the basis of the skin appearance of the affected areas, information from the anamnesis interview (pets, contact with free living cats on holiday) substantiates the suspicion. However, confirmation of the diagnosis of tinea capitis and exact identification of the pathogen using a laboratory culture and microscopic examination of individual hairs is essential. For this purpose, skin scales and hairs are extracted during the initial examination and sent to a diagnostic laboratory. The confirmation can be delayed: Since some fungal species grow very slowly, the pathogen can be detected after one week at the earliest and after five weeks at the latest.
In order to minimize the risk of infection from the patient, local treatment with sprays or ointments as well as shampoos with fungicidal agents (e.g. ciclopiroxolamine or terbinafine) is initiated immediately if tinea capitis is suspected.
If the diagnosis is confirmed, an additional systemic treatment with an orally administered antimycotic in tablet form or as a juice is indispensable: the fungus is not only present on the surface of hair and skin, but penetrates into follicles and hair shafts, to which not enough active ingredient can reach if it is applied exclusively locally.
In Germany, for a long time only the active ingredient griseofulvin was approved for the systemic treatment of tinea capitis. With this, the treatment lasted eight to twelve weeks depending on the pathogen. In the current treatment guidelines griseofulvin usually does not play a role anymore, recommended are Fluconazole for Microsporum species and Terbinafine for Trichophyton species. Intake is daily until the inflammation subsides (expected after two to four weeks), then weekly until neither fungi nor spores can be detected in cultures and microscopic examinations  .
Weekly administration of the antifungal agent and regular controls are necessary especially for Microsporum canis and Microsporum audouinii in the long term (several months) to prevent a resurgence of the infection.
Untreated, deep-reaching fungal infections can lead to the destruction of the hair follicles with scarring. If treatment is initiated in time, the prognosis is very good if the measures are carried out consistently, and the hair grows back completely.