What is Vitiligo

Vitiligo is a chronic autoimmune skin depigmenting disorder. Selective and progressive destruction or disappearance of the epidermal melanocytes of the skin results in the depigmentation of skin which is medically known as Vitiligo. The word ‘Vitiligo’ is derived from the Latin word-vitium, meaning defect or blemish.'

Vitiligo is a complex disorder that involves genetic as well as environmental factors. Not many treatment modalities are available.

How many people suffer from Vitiligo?

Approximately 1% of the world population is affected by an intriguing skin depigmentation disorder, Vitiligo.

What are the symptoms of vitiligo? 

 Typical vitiligo lesions are manifested as milky white, non-scaly macules with distinct margins. This disease has significant effects on quality of life and remains a persistent burden for the patients. Disfiguring due to vitiligo often results in patients being ostracised that affect their psychological well-being. 

What Causes Vitiligo Spots and Patches to appear?

Histological studies have confirmed the absence of melanocytes in the lesions of the vitiligo skin. Although the exact etiology of vitiligo is not known, and several theories have been put forth. Amongst them, the auto-immune theory is the most widely accepted. Interestingly, most of the vitiligo patients concurrently suffer from at least one of the other auto-immune disorders:

•    Thyroiditis
•    rheumatoid arthritis, 
•    psoriasis, 
•    adult-onset diabetes mellitus, 
•    Addison’s disease, 
•    pernicious anemia, 
•    alopecia areata, 
•    systemic lupus erythematosus etc.

This concurrent manifestation of auto-immune disorder with vitiligo suggests an underlying genetic predisposition to auto-immune diseases.  High levels of circulating anti-melanocyte auto-immune antibodies have been reported in vitiligo patients.

Melanocytes are the cells that have the unique ability to provide pigmentation to the skin. Melanocytes synthesize the pigment, melanin, which provide the color to the skin. Melanin production occurs in special organelles known as melanosomes. Enzymes present within melanosomes along with tyrosinase and tyrosinase like enzymes are critical and synthesize melanin. 

Oxidative stress results in an increase in the levels of reactive oxygen species (ROS). Accumulation of a high amount of ROS results in a structural alteration in melanocytes and the formation of antigens, which thereby stimulate the immune response of the body. This process has been named 'haptenation'. Under high oxidative stress, there is an accumulation of hydrogen peroxide species and hydrogen peroxide is an inhibitor of tyrosinase. Simultaneously, hydrogen peroxide also increases the level of reactive quinones species that act as a surrogate substrate for tyrosinase, which thereby increases the level of immunogenic neoantigens.  

Does Vitiligo affect hearing?

Another critical aspect of vitiligo is that apart from skin deformation, ocular and auditory anomalies can also occur. Melanin plays a critical role in the normal auditory function. Melanin is required for the transduction of the auditory stimuli in the inner ear. Thus, immune activation that results in auto-immune antibodies against melanocyte results in diminishing auditory functioning in vitiligo patients. 

Almost 20% of vitiligo patients suffer from the auditory loss. Similarly, vitiligo patients suffer from ocular abnormalities. Melanocytes are present in the retina as well as the iris. Thus, dysfunctional melanocytes result in ocular anomalies such as uveitis, hypopigmented spots on the iris, pigmentation on the anterior chamber, chorioretinal degeneration, etc. 

At what age Vitiligo starts?

Vitiligo can develop at any age. However, it is usually observed to develop before 30 years of age.