Alopecia areata is caused by an autoimmune reaction in which the body's immune system mistakenly attacks hair follicles, leading to inflammation and hair loss
. The exact trigger for this immune attack is not fully understood, but it is believed to involve a combination of genetic and environmental factors
. Key causes and contributing factors include:
- Autoimmune response: The immune system targets hair follicles, disrupting normal hair growth and causing patchy hair loss
. This involves T cell lymphocytes clustering around follicles and causing inflammation
- Genetics: There is a hereditary component, as alopecia areata tends to run in families. Specific genes related to immune system regulation, particularly in the human leukocyte antigen (HLA) complex, have been associated with increased risk
. Studies in identical twins show a significant genetic influence.
- Environmental triggers: Stress, illness, injury, and possibly vaccinations may trigger or worsen alopecia areata in genetically predisposed individuals
- Associated conditions: People with other autoimmune diseases such as thyroid disease, vitiligo, psoriasis, asthma, hay fever, and atopic dermatitis have a higher risk of developing alopecia areata
- Lifestyle factors: Smoking, poor sleep quality, and obesity may contribute to the onset or progression by promoting inflammation and immune dysregulation
- Nutritional factors: Deficiencies in certain vitamins and minerals like vitamin D, B3, zinc, iron, and biotin may also play a role
In summary, alopecia areata results from an autoimmune attack on hair follicles influenced by genetic predisposition and environmental or lifestyle triggers, with inflammation being the central pathological mechanism
