24 June 2021 Author : Vasco Vieira Serrão Alopecia areata is an autoimmune dermatological disease . More commonly it is characterized by localized areas of hair loss, or peels, without destruction of the hair follicles: The scalp is the most frequent location; It can also appear in the beard, alone or in association with the scalp; In the most aggressive forms of alopecia areata, the eyebrows and eyelashes can be affected; In a minority of cases, the disease may progress to total hair loss (total alopecia) or hair loss throughout the body. Alopecia areata is relatively common : It is estimated that around 2% of the population may have at least one episode in their lifetime; It affects both women and men; It appears more often in children and young adults; It does not cause physical pain, but it can have important psychological effects. Causes of alopecia areata Alopecia areata is an autoimmune disease, in other words, a disease in which the immune system responds against an element of the body itself. It has genetic influences and environmental triggers. The most common stimuli that trigger alopecia areata are: Acute stress; Infections; Sudden changes in diet; Hormonal factors. These stimuli appear to cause an immune-mediated alteration in the normal hair growth and renewal cycle, and peels forming without destroying the follicles. Thus, new hair can subsequently form from the affected follicles. Diagnosis The diagnosis of alopecia areata is based on the clinical history and on the evaluation of the affected areas . The most common presentation of alopecia areata is the sudden appearance of one or several areas without hair, usually round or oval, well defined and with the skin without visible changes. More rarely, the peels can spread and converge, reaching the entire scalp (total alopecia). In general, when a light traction is applied to the hair at the edge of the peel, it can come out of the follicle easily and painlessly. Changes in the fingernails or toenails may also be present. To reach a definitive diagnosis , other diseases that can also cause skin peels should be excluded, for example: Some fungal or bacterial infections, for example mycosis; Other autoimmune diseases; Psychiatric disorders. In a small number of patients, less than 10%, other autoimmune diseases associated with alopecia areata have been identified, particularly autoimmune thyroid diseases. Therefore, after the patient general assessment, the dermatologist may, in some situations, order laboratory tests to exclude associated diseases or other diagnoses. Treatment Localized forms of alopecia areata may resolve spontaneously with no treatment required. However, most cases benefit from a therapeutic approach . Choosing the most appropriate treatment is related to: Location, number and length of the peels; Psychological impact that the disease may have; Particularities of each patient. Localized forms usually respond well to medications: In creams, shampoos or lotions applied locally; In formulations that are injected directly into peels. In more aggressive or extensive forms , systemic medication is often used. Response to treatment is variable. In more extensive and aggressive forms of the disease, especially in total or universal alopecia, the response to treatment is generally worse. However, therapeutic alternatives for more treatment-resistant forms are available and this remains an important area of investigation. Also in the cosmetic area, today there are accessories and other solutions that help to alleviate the negative impact that alopecia areata can have on patients. Prognosis Alopecia areata has no cure and its evolution is unpredictable . It is an autoimmune, chronic, and recurrent disease. This way, the problem can be solved, but, in many people, new episodes happen again. In localized forms, the hair usually grows back, sometimes thinner and whiter at first, but eventually normalizing with growth, although it may take many months for this recovery. Some patients experience recurrent episodes of the disease throughout their lives, with complete hair recovery between crisis. In some cases, the problem may persist over the years and hair does not grow back in the affected areas. Meet the dermatology team from Hospital da Luz network and book your consultation Our Health Guide contents have an information purpose, are intended for the general public and may not be up to date. They do not substitute the individual information, opinion and advice from a doctor or other healthcare professional in each area.
