Chemical leukoderma induced by dimethyl sulfate

Chemical leukoderma: An insight of pathophysiology and contributing factors

Chemical leukoderma, or chemical-based vitiligo, is a dermal disease triggered by exposure to chemicals and characterized by the emergence of depigmentation or hypopigmentation of the skin. The etiology of this condition is associated with exposure to various chemical substances present in both occupational and non-occupational settings. The precise mechanism that underlies chemical leukoderma remains elusive and is believed to result from the demise of melanocytes, which are responsible for producing skin pigments. This condition has gained particular prominence in developing countries like India. An interesting connection between chemical leukoderma and vitiligo has been identified; studies suggest that exposure to many household chemicals, which are derivatives of phenols and catechol, may serve as a primary etiological factor for the condition. Similar to autoimmune diseases, its pathogenesis involves contributions from both genetic and environmental factors. Furthermore, over the last few decades, various studies have demonstrated that exposure to chemicals plays a crucial role in initiating and progressing chemical leukoderma, including cases stemming from occupational exposure.

[Treatment of pigmentation disorders in association with systemic diseases]

Pigmentation disorders are a frequent skin problem and incorporate a broad spectrum of diseases, caused by an abnormal melanin pigmentation or also non-melanin pigmentation of the skin. Both hypermelanosis and hypomelanosis can be hereditary or acquired. This article summarizes the treatment approaches that are used in the majority of acquired pigmentation disorders of the skin. The following forms of hypermelanosis are addressed: lentiginosis, hyperpigmentation due to endocrine disorders or other systemic diseases, drug-induced hyperpigmentation. Acquired hypomelanoses include postinflammatory hypomelanosis, chemical depigmentation, idiopathic guttate hypomelanosis and punctate leucoderma. With reference to non-melanin pigmentation, the exogenous pigmentation due to chemicals, metals and drug exposure are discussed. The treatment is primarily based on finding the cause of the alterations to the pigment. The affected area, age and ethnic origin are also important factors. The spectrum of therapeutic options is broad: topical agents, chemical peeling, systemic agents, laser and light-based treatment. As some of these treatment procedures can have side effects, the availability of a protocol that contains information on the drug concentration, dose, parameters for laser treatment and the number of sessions is important. For every disorder the specific dermatological treatment is presented even when some pigmentation alterations that occur in association with systemic diseases, are cured by the treatment of the primary disease. Most diseases are exacerbated by exposure to UV light. Therefore, sun protection is recommended and a cosmetic coverage is indicated.

Acquired disorders with depigmentation: A systematic approach to vitiliginoid conditions

Acquired disorders with depigmentation are commonly encountered by dermatologists and present with a wide differential diagnosis. Vitiligo, the most common disorder of acquired depigmentation, is characterized by well-defined depigmented macules and patches. Other conditions, such as chemical leukoderma, can present with similar findings, and are often easily mistaken for vitiligo. Key clinical features can help differentiate between acquired disorders of depigmentation. The first article in this continuing medical education series focuses on conditions with a vitiligo-like phenotype. Early recognition and adequate treatment of these conditions is critical in providing appropriate prognostication and treatment.