Melasma is an acquired and chronic disorder characterized by a localized symmetrical hypermelanosis of the face or, less frequently, involving the neck and forearms. It occurs with a high prevalence during pregnancy, especially during the second half of the gestational period, and in women taking exogenous female hormones. Melasma has also rarely been described in males, especially those affected by primary hypogonadism or taking estrogens for prostatic cancer. Melasma thus appears to be pathologically related to female sex hormones, but this is not consistently reflected in high circulating levels of estrogens or progesterone. This implies that other factors are likely to be relevant, including genetic predisposition, exposure to ultraviolet light, cosmetics and some medications. Melanocortins play a key role in melanogenesis but no cases of melasma have been described in pituitary or adrenal diseases, including those associated with an increase in serum ACTH. An association between melasma and thyroid disorders has been reported only once and not confirmed in subsequent studies. The skin is both a source of, and a target for vitamin D; however, no cases of melasma have been described in association with disordered vitamin D production. Finally, clinicians should distinguish the localized hypermelanosis of melasma from general hyperpigmentation occurring in pregnancy or in pituitary and adrenal diseases associated with a raised serum ACTH.

Melasma is one of the most common pigmentary skin disorders. It usually affects women of darker skin types, pregnant women and usually people more exposed to the sun. There are many risk factors associated with melasma, other considered to be predisposing and others considered to be triggering the disorder, when predisposition is present. Still, there are many questions to be answered, in order to better understand its pathophysiology, which will finally lead us to better medication and less relapses of melasma.

Known since ancient times, melasma is notoriously a frequent dyspigmentation disorder characterized by localized, chronic acquired cutaneous hypermelanosis. Despite high frequency, significant negative effects on quality of life and often unsatisfactory results of available treatment, not much research has been performed on the etiopathogenesis of this disease, which still remains largely obscure. An extensive review of the literature on etiology and pathogenesis of melasma is presented here, in which known causal/exacerbating factors (sun exposure, alterations of hormonal balance, use of cosmetics and photosensitizing drugs, procedures and inflammatory processes of the skin, stressful events) are linked with their effects on multiple metabolic pathways of melanocytes and other components of the socalled “melanin unit”. Available data outline an incompletely defined, but certainly complex and somehow fascinating network of interactions of structural and functional alterations, which deserves further investigation, not only to obtain new and better treatments for melasma, but also –and probably more important in view of a more detailed understanding of the entire physiology and pathophysiology of melanogenesis, with many possible applications in the vast field of dyspigmentation disorders

Melasma (synonymum chloasma) is an acquired hypermelanosis found typically in sun-exposed areas. Melasma affects predominantly women (90%), however it can be a serious cosmetic problem for men, too. This article describes melasma in men, its pathogenesis and treatment options.

Background: Melasma is a common acquired disorder of hyperpigmentation mainly located on the face. Classification and clinical evaluation of melasma is the first step of any therapeutic strategy. Reflectance Confocal Microscopy (RCM) is a novel, non-invasive technique that offers an in vivo analysis of the skin layers at a cellular level resolution.
Objective: To assess the efficacy of the application of RCM in the diagnosis and management of melasma. Methods: A search of all the available literature concerning the use of RCM in melasma was performed on Pubmed Medline. In total ten papers were selected and reviewed.
Results: Melasma seems to exhibit a specific pattern in RCM analysis. Correlation of histopathology and RCM revealed common findings among the relevant studies. Epidermal hyperpigmentation – a hallmark of melasma - is represented as a honeycombed pattern, mottled pigmentation and strongly visible papillary rings around the dermal papillae, composed by a sequence of brighter cellular structures at the level of the dermo-epidermal junction. Dermal melanin has the appearance of plump bright particles corresponding to melanophages. RCM reveals an epidermal portion in all melasma lesions rendering obsolete the up to present classification of the disease, which is based on Wood’s lamp examination. Even clinically undetectable changes during melasma treatment can be detected by means of RCM analysis introducing the technique as a highly sensitive tool for the monitoring and evaluation of treatment.
Conclusion: RCM emerges as a reliable adjuvant technique for the classification, diagnosis and overall management of melasma. Further studies need to be conducted in order to investigate the prospective of in vivo RCM in melasma.

Melasma is a common skin disease involving changes in normal skin pigmentation. It results from epidermal melanocyte hyperactivity that causes increased production and accumulation of melanin. The onset of the disease has been associated with sun exposure, drugs, genetic and hormonal factors. The primary focus of this review was to provide an updated overview of the main biological aspects behind skin pigmentation and melasma development.
As a second aim of this review, the main mechanisms by which different compounds could reduce melanogenesis were also discussed. Common hypo-pigmenting agents act by reducing the melanogenesis through several mechanisms; they can affect melanin transcription and glycosylation, inhibit tyrosinase (a pivotal enzyme in melanin synthesis), slow the melanosome transfer or increase the skin turnover. Although a number of skin-lightening agents were proposed for treatment of hyperpigmentary disorders, none of these has achieved satisfactory effects. In this light, the most recent therapeutic strategies for melasma, and emerging molecular targets to control skin pigmentation, such as MITF, Wnt and mTOR, were herein described.

Melasma represents the most common pigmentary disorder occurring in pregnancy. It mainly consists in a hyperpigmentation of the face and neck, due to an alteration of melanocytes’ density and of melanin’s concentration. At first sight it may appear to be a minor clinical condition, without vital risk, but clinicians consider it as an important cosmetic stigma difficult to treat and that may cause great emotional suffering.