Effect of chemical exposure in induction and evolution of vitiligo: Correlation between duration of exposure and disease, site of exposure and onset, and impact upon avoidance

Abstract

Leucoderma Chemical exposure a b s t r a c t Background: The exogenous oxidants can trigger and lead to progression and chronicity in idiopathic vitiligo similar to chemical leucoderma and contact vitiligo. Aims: The basic objectives of this study were to study chemical exposure history in vitiligo patients and to correlate this with induction or progression of lesions. Methods: This prospective observational study with intervention in the form of avoidance of exposure was conducted at MGM Medical College, Bihar at eastern India during the period of September 2010 to April 2012. Detailed record of demographic and clinical features was noted with specific chemical exposure especially duration of exposure, site of exposure, and outcome of the disease upon avoidance of chemicals. Results: The proportion of cases coming to the OPD with vitiligo was 1.03% (n = 241) among total 23,410 outpatients department's dermatological patients. History of household chemical exposure and industrial (occupational) chemical exposure was found in 94.6% (n = 228) and 0.4% (n = 1) patients, respectively. The duration of disease and duration of chemical exposure had no correlation (r = +0.1756). Regarding avoidance of chemical exposure on the progression of vitiligo, the difference between fully compliant versus noncompliant was statistically significant (p < 0.05) but between partial compliant versus noncompliant was not significant (p > 0.05). Correlation of site of chemical exposure with site of onset of disease was found in 64.9% (n = 148) patients. Conclusions: Chemical triggering factors play very significant role in induction and progression of vitiligo.

Antioxidant properties and antibacterial activity of fermented Monascus purpureus extracts

“…Phenolic derivatives are structurally similar to the melanin precursor tyrosine, and therefore tyrosinase was originally implicated as a mediator of cytotoxicity, Phenolic compounds may be used as depigmenting agents and because they have a similar chemical structure to tyrosine, the substrate of tyrosinase. 37 Kojic acid and total phenols content, add nitrogen source can increase 0.89~0.54; 1.24~2.26 fold, respectively. Inhibition tyrosinase activity also can increase 0.59~1.55 fold ability (Table 1).…”

Chemical vitiligo: A subset of vitiligo

“…In another study,[ 36 ] we have been able to show that chemical triggering factors play a very significant role in the induction and propagation of vitiligo. History of household chemical exposure and industrial (occupational) chemical exposure were found in 94.6% and 0.4% of the patients, respectively.…”

Melanogenesis and Hypopigmentation

“…The mechanism of chemical-induced vitiligo is complex and still not clear. [ 38 39 ] It has been observed that some chemicals such as monobenzyl ether of hydroquinone (MBEH) and 4-tertiary butyl phenol can downregulate microphthalmia-associated transcription factor (MITF) leading to decreased melanin synthesis and thereby initiation of vitiligo. [ 40 ] MBEH was the first chemical known as causing depigmentation and nowadays, MBEH is approved by the US Food and Drug Administration (FDA) and is used therapeutically to complete and accelerate depigmentation to make the skin tone of patients with severe vitiligo uniform.…”