Vitiligo and Chemicals How Are They Related? It is thought that one of the triggers of vitiligo is exposure to chemicals.
Vitiligo is an autoimmune disease that presents with depigmented patches.
Vitiligo and Chemicals What Does Scientific Research Say?
Several studies have been conducted on different chemical compounds which in most cases contain phenolic groups (organic compounds contain at least one carboxyl group) in their chemical structure.
Since the phenol group forms a part of the amino acid tyrosine, the precursor of melanin, it has been hypothesized that phenol-containing compounds act as analogues of tyrosine.
These, in fact, come into contact with the skin thus interfering with the production of melanin.
Other studies have speculated that depigmenting chemicals produce metabolites, intermediate products of metabolic reactions catalyzed by various naturally occurring enzymes within cells, which are toxic to melanocytes.
Furthermore, they hypothesized that these substances overwhelm the ability of melanocytes to resist oxidative stress.
Exposures to chemicals in the workplace have been shown to increase the chances of this skin disease on the hands and forearms as well.
However, other studies have observed how vitiligo could appear in other areas that are not in direct contact with chemicals.
This latter observation led to the invocation of the autoimmune theory, proposing that chemical-induced stress in melanocytes initiates an autoimmune response, leading to their destruction.
Subsequently, the immune response can affect other melanocytes in distant regions that are not in direct contact with the chemical.
Diagnosis
Chemical associated vitiligo poses a diagnostic challenge, as it is often difficult to differentiate from primary vitiligo on the basis of clinical and histopathological presentation.
The presence of 3 of the following 4 criteria is considered sufficient to establish the diagnosis of chemical-associated vitiligo:
- depigmented spots similar to vitiligo
- history of repeated exposure to specific chemical compounds
- Vitiligo-like spots at the site of exposure and coriander-shaped macules.
A thorough medical history is essential for diagnosing chemical-associated vitiligo and identifying the underlying cause.
Presumably, this type of vitiligo does not confer the same increase in associated autoimmune conditions as normal vitiligo, although this is not well studied.
In many cases, avoiding the offensive chemical agent allows the condition to resolve itself.
Additionally, chemical-associated vitiligo tends to respond better to direct skin treatments than normal vitiligo.
