Skin
A Sahib El-Radhi, James Carroll in Paediatric Symptom Sorter, 2017
Pigmentary disorders are a common presentation to general practitioners, paediatricians and dermatologists. In some cases, pigmentation is an external sign of a serious underlying systemic disorder. In general, children who present with multiple or generalised hyperpigmented lesions have a more serious underlying disease than those who present with isolated lesions. Increased pigmentation, caused by deposition of melanin, may be due to hormonal changes, e.g. pregnancy, or increased melanogenesis as in haemochromatosis. It may be generalised or localised, result from defects in melanocyte formation, production, differentiation, migration or distribution. Hypopigmentation or depigmentation indicates a congenital or acquired decrease in melanin production. In some cases, e.g. tuberous sclerosis (TS), hyper-and hypopigmented lesions occur.
Noninvasive Tests
Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan in Comprehensive Textbook on Vitiligo, 2020
The utility of dermoscopy in the diagnosis of vitiligo is now well established. Chuh and Zawar noted a pattern of depigmentation with residual reservoirs of perifollicular pigment signifying focally active or repigmenting vitiligo [4]. Meng et al. studied 176 patients with various types of depigmentation, of whom 97 had vitiligo. They observed residual perifollicular pigmentation in 57 (91.9%) of 62 patients with progressing vitiligo and 22 (62.9%) of 35 with stable vitiligo [5]. However, residual perifollicular pigmentation was absent in the 79 patients with non-vitiligo depigmentation. The presence of telangiectasia, early reservoirs of pigmentation, and perilesional hyperpigmentation were related to the stage of vitiligo and treatment history of patients [6]. Various dermoscopic findings are associated with stability and repigmentation of vitiligo. These include marginal and perifollicular hyperpigmentation, reticular pigmentation, and marginal reticular pigmentation. Reduced pigmentary network, absent pigmentary network, reversed pigmentary network, perifollicular hyperpigmentation, and perilesional hyperpigmentation are seen in the evolving vitiligo lesions.
Endocrine system
Aida Lai in Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Nelson’s syndrome Occurs after bilateral adrenalectomyCharacteristic pituitary adenoma and high ACTH levelsSigns: – pigmentationManagement: – surgical resection of pituitary gland– radiotherapy
Macro images of culture plates
Published in Journal of Visual Communication in Medicine, 2019
Geraldine Thompson
The macro images of these culture plates demonstrate the characteristics of growth in the medium used (usually blood agar or agar). These are the characteristics used to accurately and consistently describe the morphology of a colony, and these are categorised as follows: Size.Shape.Colour (also known as pigmentation).Texture.Height (a.k.a. elevation).Edge (a.k.a. margin).
Development of piperine nanoemulsions: an alternative topical application for hypopigmentation
Published in Drug Development and Industrial Pharmacy, 2022
Burcu Ozkan, Ebru Altuntas, Rabia Cakir Koc, Yasemin Budama-Kilinc
Melanin biosynthesis is a complex mechanism that occurs within melanocytes, very specialized pigment cells within membrane-bound organelles called melanosomes [1]. Melanogenesis has different stages, and when this process is disrupted, different types of pigmentation disorders can be seen, classified as hypo- or hyperpigmentation [2,3]. Melanocytes are largely destroyed in hypopigmentation disorders such as vitiligo due to the loss of functional epidermal melanocytes. Therefore, depigmented lesions occur on the skin [4]. Vitiligo is a common disease affecting 0.5–2% of the general population. This bothersome disease begins on average at the age of 20 but is most common between the ages of 10 and 30 [5]. This apparent disorder can lead to many psychological, social and physiological problems in individuals [6].
An emerging technology in lipid research for targeting hydrophilic drugs to the skin in the treatment of hyperpigmentation disorders: kojic acid-solid lipid nanoparticles
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Khadijeh Khezri, Majid Saeedi, Katayoun Morteza-Semnani, Jafar Akbari, Seyyed Sohrab Rostamkalaei
Pigmentation disorders are one of the most common skin diseases that are caused by abnormal distribution, structure and function of melanocytes. The pigmentation disorders’ treatment has always been challenging and discouraging for the most population especially women. The most middle-aged women have often abnormal pigmentation on their facial skin and these skin disorders are related to various endogenous and exogenous agents [4]. Pigmentation disorders can be expressed in two forms of skin pigmentation increase (hyperpigmentation) and decrease (hypopigmentation). These skin pigmentation disorders can cause aesthetic, cognitive and psychological challenges for the patients and have psychosocial effects on them. Common typical pigmentation disorders including melasma (chloasma) and ephelides (freckles) are related to disturbance in skin pigmentation [5–7].
Related Knowledge Centers
- Absorption
- Chromatophore
- Color
- Eye
- Skin
- Melanin
- Fur
- Hair
- Structural Coloration
- Reflection