டெர்மட்டாலஜி மற்றும் டெர்மட்டாலஜிக் நோய்களுக்கான ஜர்னல்

Oral mucosa under physiological condition contains a certain degree of chromic variation. Differentiating such physiological variations from pigmented lesions appears challenging without a histopathological confirmation. In several oral lesions, pigmentation is a part of the primary pathology or a secondary change to an existing entity. The pigments involved in both physiological and pathological conditions can be broadly categorised as exogenous or endogenous. Among these, melanin accounts for the majority of black to brown pigmentation including malignant melanoma. Clinically, their biological behaviour shows an ambiguity which makes it challenging to arrive at diagnosis for even the experienced practitioner. Although biopsy confirms and reassures the patient, it is impractical to biopsy all pigmented lesions. The standard diagnostic algorithm given below is to aid the clinician to diagnose and treat this diverse group of lesions.

Skin pigmentation is an important human phenotypic trait that gives special aesthetic hue to individuals and also protective covering against solar ultra violet radiations, but excessive pigment production and uneven distribution, appear as serious undesirable hyperpigmentory anomalies. To overcome this, various therapeutic agents and skin-lightening cosmetics are in big demand across Asia, and the quest for fairness has led to identification of many new ingredients. The mechanisms underlying pigmentation has been researched extensively and the knowledge are being updated regularly. To understand the etiology of normal and uneven skin pigmentation, first part of the review serves us basic updated information regarding the normal process of melanogenesis and strict coherent attributes that monitor the skin pigmentation control machinery. While the later part of the review focuses on some abnormal hyperpigmentory anomalies, their mode of action at the cellular level and various approaches that exploit the natural botanicals for their permanent and cost effective treatment.

Background: Melasma is a common disorder of hyperpigmentation affecting millions of people worldwide. All the exact pathways to understand the complete pathogenesis of melasma is unknown. Aims: To determine the biophysical characteristics of melasma skin compared to the normal surrounding skin.
Methods: Thirty-six patients with melasma were recruited in this case-control study. The subtype of melasma (epidermal, dermal, or mixed) was determined by Wood lamp examination. The melanin index, erythema index, stratum corneum (SC), hydration, sebum content, transepidermal water loss (TEWL), temperature, friction index, and pH of lesional and perilesional normal skin of patients were measured in standardized temperature and humidity conditions. The epidermal and dermal thickness and dermal echo-density were determined on the same locations. The measurements were compared between lesional and perilesional normal skin using dependent t-test and among three subtypes of melasma using one-way ANOVA. P values of <0.05 were considered statistically significant. Results: Melanin index, erythema index, SC hydration, pH, thickness of dermis and epidermis were significantly higher and the temperature was significantly lower in lesional skin compared with surrounding normal skin. No significant differences were found in TEWL, friction index, sebum content and density of dermis. Melasma subtype, age, skintype, location and duration of melasma had no significant effect on any of these variables.
Conclusions: Melasma skin is characterized by certain changes in biophysical factors of epidermis and dermis. The relation of these changes with the hyper-activity of melanocytes and melanin overproduction should be determined in future studies. Keywords: Melasma; Melanin; Skin; Biophysical characteristics

Skin color has always been important and interest to people in all cultures. Disorders of skin color, either hyperor hypopigmentation are cosmetically vexing and can be signs of systemic disease. For many centuries physicians have tried to treat such disorders. We review some of the history of treatments for hyperpigmentation and the development of hydroquinone, currently the medication of choice for hyperpigmentation.

Vitiligo is a disorder of pigmentation characterized by the development of depigmented macules and patches. The etiology is multifactorial, including immune mediated destruction of melanotytes. Several autoimmune conditions are associated with vitiligo, but thyroid disease is the most common. In this case report, we describe a patient with rapidly depigmenting vitiligo who stabilized on narrowband UVB (NBUVB) phototherapy and oral corticosteroids, and began showing dramatic repigmentation once thyroid replacement was initiated. This highlights the interplay between vitiligo and autoimmune thyroid disease, as well as the need for adequate treatment of both disorders to achieve optimal treatment response.

Background: Melasma is a commonly encountered pigmentary disorder in dermatology practice. This study is aimed at studying the epidemiology, clinical presentation, and precipitating and/or provocation factors associated with melasma.

Methods: Total 120 patients with melasma were enrolled. The demographic data was recorded and clinical evaluation was done.

Results: Female to male ratio was 3.28:1. Mean age of onset of melasma was 29.4 years. Mean duration of melasma was 4.51 years. All patients reported moderate to chronic photo exposure as an aggravating factor for melasma. Total 52.17% females experienced exacerbation of melasma during pregnancy. MASI score was ranging from lowest being 4.5 whereas highest being 38.6. Mean MASI score was 16.94. Evaluation with Wood’s lamp showed 50% patients had epidermal melasma.

Conclusion: This study indicates that melasma has multifactorial etiology such as photoexposure and hormonal influences such as pregnancy, intake of oral contraceptive pills and thyroid disorders. We also found family history of melasma in some of our patients.