Alopecia is the disease that consists in general or localised loss of hair from the head or the body. It has major psychological and social impact on patients, as a rich head of hair has always been an important beauty feature in both sexes. The hair follicle consists of the follicle proper and the hair bulb, which creates the hair, its strain and the sebaceous gland. Any damage to the follicle or bulb can cause alopecia. The growth cycle of hair consists of the anagen phase (growth), the catagen phase (transition) and the telogen phase (shedding). Disturbance of any of these phases results in alopecia. Normally 90-95% of the hairs are in the anagen phase and 5-10% in the telogen phase, and a loss of 50 to 100 hairs a day is normal. When the rate of loss increases over 100 hairs a day, alopecia can be observed. This is called telogen effluvium. This form of hair loss is common in iron deficiency anaemia and endocrine and metabolic diseases. Any disturbance of the anagen (growth) phase of the hair causes anagen alopecia. This form is observed during the use of chemotherapeutic substances and radiation for malignant diseases.
Alopecia – Causes
It can be caused by hereditary or hormonal factors, chronic inflammations, diabetes, or fungal infections. Other frequent causes are thyroid disease, hypervitaminosis A, iron deficiency and poor nutrition. Surgery and childbirth can cause transient alopecia. Anxiety and stress, constant pulling of hair during brushing, and hair styling techniques can lead to traction alopecia. There are also cases of alopecia that have an autoimmune aetiology, such as pathological cicatricial alopecia in case of lichen planus, systemic lupus erythematosus, scleroderma, etc. Also, chronic use of certain medications, for example such as antidepressants, cortisone or hormonal preparations, can cause hair thinning, hair loss and eventually alopecia, which in most cases is reversible if the medication is discontinued.
The most common form in men, in a percentage of more than 90%, is androgenetic alopecia (male pattern hair loss, commonly known as baldness), while in women, androgenetic alopecia is the cause in about 50% of cases. The most common form in children is alopecia areata (spot baldness) and traction alopecia, which is due to pulling the hairs and usually has psychological roots.
One other quite frequent form is localised traumatic alopecia, resulting from injuries, burns, accidents etc. Also, there are frequent cases of traumatic alopecia as a result of a previous hair transplantation with the older strip technique or FUT, as this technique always leaves a postoperative scar in the donor site in the occipital region of the head. Traumatic alopecia usually involve the scalp, but can also involve facial hair, especially the eyebrows and beard.
Alopecia – Clinical picture
The clinical picture of alopecia includes hair loss, skin lesions, and potentially scarring. Hair loss happens gradually; usually, the observation of an area suffering from androgenetic alopecia shows thinning of hairs, which are largely in the telogen phase and with each new life cycle lose the dynamic of growth and gradually deteriorate. A long process of thinning and degeneration follows, called miniaturisation, until the hairs reach their final point of degeneration, the hair follicle disappears, and the remaining hairs look like a transparent, thin fluff (terminal hair, vellus hair). The pattern of androgenetic alopecia in men consists in thinning or complete lack of hair in the frontal, temporal and parietal regions, while the occipital area is spared. Androgenic alopecia in women shows a more diffuse form, normally with retention of the front hairline, thinning in the frontal and parietal regions, and maintained hair growth in the occipital region. In women, the total lack of hair in a particular area is extremely rare compared to men, in whom it is extremely frequent. The continuing growth of hair in the occipital and lateral temporal regions, even in old age, is a feature that is observed worldwide and defines the so-called ‛constant hair growth zone’, which serves as a donor site for hair transplantation. At a microscopic level, it has been found that the hair follicles in the constant hair growth zone do not have androgen receptors, making them less susceptible to the action of male hormones and subsequent hair
loss. It can be circumscribed (patchy), diffuse or total. It is also divided in cicatricial (scarring) and non-cicatricial (non-scarring).
Alopecia – Diagnosis
The diagnosis is the most important step to proper treatment. The diagnostic tests are:
- Pull test. With this test, the doctor will gently pull the hair and then evaluate how many hairs are left in his hand.
These hairs are then examined microscopically for the diagnosis of alopecia. This is the classical diagnostic method known as trichogram.
The classic trichogram gives conclusions about the number and the ratio of hairs that are in the anagen and in the telogen phase, thereby determining if the balance between the hair growth phases has been disturbed. It can also show if there are dystrophic hairs that do not develop properly, and whether there are damages to the bulb or the hair shaft that cause the alopecia.
- A scalp skin biopsy helps in the correct diagnosis, when there are issues with the differential diagnostic. It is particularly useful in cases with an unclear clinical picture, alopecia areata and cicatricial alopecia.
- Finally, the most modern method of determining alopecia is the phototrichogram, with the use of a special digital microcamera. At Advanced Hair Clinics, we use this method for the evaluation of alopecia and the suitable treatment option. More specifically, using the special “Follysis” software, photos of both the affected area and the healthy areas of the scalp are digitally analysed. The extent of the affected area, the number of follicles and the average number of hairs per follicle, as well as the hair shaft diameter are determined and compared with reference values from the healthy area of the scalp. A decreased strand diameter is an early indication of development or progression of alopecia in the examined area.