Alopecia is defined as the reduction of the quantity of hair at the level of the areas where it is normally located. Alopecia should be differentiated from atrichia, which is the congenital lack of hair due to the absence of pilous follicles and from hypotrichosis, which is the reduction of the quantity of hair as a consequence of congenital conditions. The presence of alopecia causes aesthetic and psychological problems.
Androgenic Alopecia
Represents 95% of the overall number of alopecia cases and it consists of the progressive loss of hair, caused by genetic factors, and occurring in most men and in some women localized in the frontal and parietal regions.
It is characterized by:
- an onset at the level of the frontal and temporal regions or at the level of the vertex;
- in men: a family history of androgenic alopecia in 1st or 2nd degree relatives;
- in women, possibly associated to menstrual disorders (amenorrhea or oligomenorrhea) and polycystic ovary, hirsutism or virilization, history of infertility.
Alopecia areata (or pelada)
Represents an inflammatory local hair loss, of unknown cause and with an unpredictable evolution. It may be associated to autoimmune diseases or immunity unbalances, the presence of certain factors that indicate the autoimmunity of the disease being described.
It is characterized by:
- the loss of hair under the form of well-defined radially expanding round plaques;
- the associated eyebrow, eyelashes, axillary, pubic hair alopecia.
Telogen Effluvium
Is a temporary, diffuse hair loss, involving a shortening of the pilous follicle evolution cycle accompanied by an increase in the telogen hair rate.
It is characterized by:
- the reduction of the density of hairs at the level of the scalp, diffused or sometimes more pronounced at the level of the parietal region;
- the onset frequently occurs under the influence of one of the following possible triggers: iron deficiency anaemia, hyper or hypothyroidism, postpartum, improper diet, oral birth control or its interruption, following the administration of certain types of medication (hormones, antihyperlipidemic agents, anticonvulsants, cytostatic drugs, antihypertensive drugs, psychotropic drugs, etc.), the accidental exposure to toxic substances, chronic kidney disease, the altered hepatic function, secondary syphilis).
