Eyebrows are curved hairs located on the brow bones. Eyebrow hair follicles share the same basic structure with hair follicles found in other parts of the body, but they are distinguished by a shorter anagen (growth) phase (Nguyen, J., 2014).
Eyebrows function to protect the eyes from sweat and provide shade. Eyebrows, which are also important for facial expression, surround the eyes along with eyelashes, cheekbones, hairline and nose; and thus, contribute to the facial appearance of the individual.
MAIN CAUSES OF EYEBROW HAIR LOSS
Atopic dermatitis is a type of eczema that causes red and itchy patches on skin. Atopic Dermatitis can damage the skin around the eyes, causing to the loss of eyebrow hair.
Alopecia areata is a temporary hair loss that damages the hair follicles because of the immune system. Any area of hairy skin, including the eyebrows, can be affected by alopecia areata.
Hypothyroidism, or underactive thyroid gland, affects the scalp and the growth of body hair negatively. Thinning of the eyebrows can occur as a late symptom of hypothyroidism.
Other Medical Conditions
Nutritional disorders and some dermatological diseases can also cause eyebrow hair loss (Tina M. et al., 2017).