The appearance of blonde or white eyelashes, known as poliosis, represents a localized loss of color in the hair shaft. This change occurs when the natural pigment is no longer being deposited into the eyelash hair. Understanding this phenomenon involves looking closely at the cellular mechanisms responsible for hair color and what can disrupt them.
The Biological Process of Pigment Loss
Hair color is determined by melanin, a complex pigment synthesized by cells called melanocytes located within the hair follicle. These melanocytes produce two main types of melanin: eumelanin (brown and black shades) and pheomelanin (red and yellow tones). The final color of an eyelash depends on the quantity and ratio of these pigments transferred to the hair shaft’s cortex.
Poliosis occurs when there is a reduction in the number of active melanocytes in the eyelash follicle or a disruption in their ability to produce melanin. This pigment loss is often the result of damage or premature depletion of these pigment cells. Damage to the melanocytes at the base of the follicle prevents the proper coloration of the new hair as it grows, causing the hair shaft to lack pigment.
Systemic Health Conditions Causing Depigmentation
Eyelash depigmentation can signal an underlying systemic health issue, particularly those involving the immune or endocrine systems. The autoimmune condition vitiligo, which causes the skin to lose pigment in patches, is a frequent cause of poliosis when it affects the eyelid area. Here, the immune system mistakenly attacks and destroys the melanocytes in the skin and hair follicles.
Alopecia areata, an autoimmune disorder known for causing patchy hair loss, can also target the pigment cells in the eyelashes. Thyroid disorders, particularly hypothyroidism and autoimmune thyroiditis like Hashimoto’s, are frequently seen alongside poliosis. These hormonal imbalances can interfere with the processes governing hair growth and pigmentation. Nutritional deficiencies, such as low levels of Vitamin B12 or copper, have also been correlated with depigmentation, as these nutrients play a role in melanin synthesis.
External and Environmental Triggers
Beyond internal health conditions, external factors can directly cause or contribute to eyelash poliosis. Certain medications are known to have depigmentation as a side effect, most notably topical prostaglandin analogs used to treat glaucoma. These eyedrops can sometimes lead to a localized lack of pigment in the eyelashes, eyebrows, or surrounding skin.
Inflammation or physical trauma near the hair follicle can also disrupt melanocyte function. Chronic inflammation, such as that caused by severe blepharitis or eye infections, may damage the pigment-producing cells. Reactions to cosmetic products, including mascaras, eyelash dyes, or lash serums, can trigger localized allergic or inflammatory responses. Even repeated friction or physical irritation can contribute to the disruption of the pigment machinery in the hair follicle.
When to Seek Medical Consultation
If you notice a sudden or rapidly progressing change in your eyelash color, consult a healthcare professional. A doctor can determine if the poliosis is an isolated occurrence or a symptom of a broader health issue. Warning signs that warrant medical evaluation include the concurrent development of white patches on the skin (leukoderma), rash, eye inflammation, vision changes, or generalized hair loss.
Your primary care physician or a dermatologist can perform a thorough examination and may order blood tests to check for autoimmune markers or nutritional deficiencies. An ophthalmologist may also be consulted if topical medication side effects or eye-related inflammation are suspected. Identifying and addressing any underlying condition is necessary for health management.