25 June 2021 Author : Vasco Vieira Serrão Telogen effluvium is a type of alopecia, or hair loss, due to disorders in the growth and renewal cycle of the hair . Under normal circumstances, hair growth and renewal takes place cycles with three phases: About 90% of hair follicles are in the growth or anagenesis phase; About 3% are in transition or catagenesis phase; About 7% are in the resting or telogenesis phase, in which there is no longer any hair growth and that ends with its loss. The growth and renewal process is not synchronized and normal hair loss is around 100 hairs a day. In telogen effluvium, by the action of a stimulus , the proportion of hair follicles in telogenesis increases . This results in a premature fall of many hairs and increases the number of hairs lost per day. It is estimated that 7%-35% of the follicles that in a normal situation would be in anagenesis can enter telogenesis. Telogen effluvium is a very common type of hair loss, especially in women. When intense, the effluvium can lead to a transient reduction in hair mass, which is due to the time it takes for the hair to grow after and contributes to the normalization of the hair mass. In this type of alopecia, hair loss is diffuse and there is no progression to baldness. Causes of telogen effluvium Several stimuli, internal or external, isolated or not, can be the cause of telogen effluviumThe most frequent stimuli are: Childbirth; Surgeries; Acute illnesses; Sudden weight loss; Nutritional deficiencies; Hormonal disorders; Intense stress; Some medications. Diagnosis The diagnosis of telogen effluvium is based on clinical history and disease presentation . In some cases, it may be necessary to perform laboratory tests to exclude possible causes. More rarely, other diagnostic tests are needed. Acute telogen effluvium is the most frequent form of the disease: It happens at any age, including in children; Usually appears 2-3 months after the stimulus that causes it; It installs quickly and is self-limiting once the stimulus is removed; Normalization of hair mass may take 6-12 months. Chronic telogen effluvium is rarer: It most affects women aged 30-60 years; Its cause is not known; It lasts longer than 6 months, it may even persist for years. Treatment When the cause that triggered the hair loss is identified or resolves spontaneously, the effluvium is self-limited. Once the stimulus that triggered is over, the hair renewal and growth process returns to normal. Correcting the cause , when necessary, is often the most important part of treatment. It may be necessary to involve other specialists , in addition to dermatology, for example when there are: Nutritional deficits; Hormonal disorders or other underlying illnesses; Need for psychological support. In other cases, no intervention may be necessary other than informing that the hair will grow back, but that it may take 6-12 months for the complete normalization of the hair mass. Follow-up evaluation in dermatology may be advised and medications are sometimes used to help with a faster recovery from the telogen effluvium. Meet the dermatology team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
