Laugier-Hunziker syndrome is a rare idiopathic acquired hyperpigmentation of oral mucosa and lips which is often associated with longitudinal melanonychia. This condition is known to be an entirely benign disease with no systemic manifestations. Herein we report a case of a 54-year-old woman presenting with a 7-year history of asymptomatic oral pigmentation and linear pigmented streaks of sever...

Current opinion holds that pigment cells, melanocytes, are derived from neural crest cells produced at the dorsal neural tube and that migrate under the epidermis to populate all parts of the skin. Here, we identify growing nerves projecting throughout the body as a stem/progenitor niche containing Schwann cell precursors (SCPs) from which large numbers of skin melanocytes originate. SCPs arise...

The expression of ectopic olfactory receptors (ORs) in melanized cells, such as the human brain nigrostriatal dopaminergic neurons and skin melanocytes, is here pointed out. ORs are recognized to regulate skin melanogenesis, whereas OR expression in the dopaminergic neurons, characterized by accumulation of pigment neuromelanin, is downregulated in Parkinson's disease. Furthermore, the correlat...

The differential diagnosis of bluish-gray pigmentation of the skin includes dermal melanocytosis, malignant melanoma and metallic discoloration. Of these disorders, metallic discoloration, which develops from deposits of fine metallic particles on the skin, is an uncommon dermatologic disease. We report a case of metallic discoloration of the right shin caused by titanium alloy prostheses in a ...

Amyloidosis cutis dyschromica (ACD) is an extremely rare type of primary cutaneous amyloidosis. To date there are fewer than 40 published cases worldwide; some were reported affecting several family members. Its resemblance to other common pigmentation disorders makes it rarely recognized at first sight. Our patient, the 12-year-old firstborn son of non-consanguineous parents presented with gen...

Tyrosinase-related protein 1 (TYRP1) is one of three tyrosinase-like glycoenzymes in human melanocytes that are key to the production of melanin, the compound responsible for the pigmentation of skin, eye, and hair. Difficulties with producing these enzymes in pure form have hampered the understanding of their activity and the effect of mutations that cause albinism and pigmentation disorders. ...

In this article, we are collectively presenting case reports of 15 patients who developed pigmentary changes of the skin and mucus membrane during the course of chloroquine therapy for connective tissue disorders. These female patients developed hyper pigmentation of the skin, largely on the exposed parts of the body. The pigmentary changes varied from brownish/ grayish/ bluish-black in color, ...

The association between pregnancy and altered cutaneous pigmentation has been documented for over two millennia, suggesting that sex hormones play a role in regulating epidermal melanocyte (MC) homeostasis. Here we show that physiologic estrogen (17β-estradiol) and progesterone reciprocally regulate melanin synthesis. This is intriguing given that we also show that normal primary human MCs lack...

The purpose of this study was to understand the impact altered polyamine levels on epidermal pigmentation. We used laser-capture microscopy and human primary melanocyte culture establish mechanisms by which polyamines function significance their misregulation in Melasma. are ubiquitously expressed cations that essential for a wide array cellular events. Changes intracellular can have regulatory...

Vitiligo is a common chronic acquired pigmentation disorder characterized by loss of functional melanocytes from the epidermis and follicular reservoir. Among multiple hypotheses which have been proposed in the pathogenesis of vitiligo, autoimmunity and oxidative stress-mediated toxicity in melanocytes remain most widely accepted. Macroautophagy is a lysosome-dependent degradation pathway which...