Tinea versicolor is a condition characterized by a skin eruption on the trunk and proximal extremities. The majority of tinea versicolor is caused by the fungus Malassezia globosa, although Malassezia furfur is responsible for a small number of cases. These yeasts are normally found on the human skin and become troublesome only under certain circumstances, such as a warm and humid environment, although the exact conditions that cause initiation of the disease process are poorly understood.
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary gland.
Melanism is the congenital excess of melanin in an organism resulting in dark pigment.
Acanthosis nigricans is a medical sign characterised by brown-to-black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds, such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead and other areas.
Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.
Periorbital dark circles are dark blemishes around the eyes. There are many causes of this symptom, including heredity and bruising.
Melasma is a tan or dark skin discoloration. Melasma is thought to be caused by sun exposure, genetic predisposition, hormone changes, and skin irritation. Although it can affect anyone, it is particularly common in women, especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy medications.
A concealer or color corrector is a type of cosmetic that is used to mask imperfections on the skin. These imperfections can include dark circles under the eyes, blemishes, and hyperpigmentation. Concealer is similar to, and can be used in conjunction with foundation, a lighter cosmetic that is used to even out the skin tone. Both concealer and foundation are typically used to make skin appear more uniform in color. These two types of cosmetics differ in that concealers tend to be more heavily pigmented, though concealer and foundation are both available in a wide range of colors opacities.
Ochronosis is a syndrome caused by the accumulation of homogentisic acid in connective tissues. The condition was named after the yellowish (ocher-like) discoloration of the tissue seen on microscopic examination. Macroscopically, though, the affected tissues appear bluish-grey because of a light-scattering phenomenon known as the Tyndall effect. The condition is most often associated with alkaptonuria, but can occur from exogenous administration of phenol complexes such as hydroquinone. It was first described by Rudolf Virchow in 1865.
Azelaic acid (AzA) is an organic compound with the formula HOOC(CH2)7COOH. This saturated dicarboxylic acid exists as a white powder. It is found in wheat, rye, and barley. It is a precursor to diverse industrial products including polymers and plasticizers, as well as being a component of a number of hair and skin conditioners. AzA inhibits tyrosinase.
Periorbital cellulitis, or preseptal cellulitis, is an inflammation and infection of the eyelid and portions of skin around the eye anterior to the orbital septum. It may be caused by breaks in the skin around the eye, and subsequent spread to the eyelid; infection of the sinuses around the nose (sinusitis); or from spread of an infection elsewhere through the blood.
Nevus of Ota is a hyperpigmentation that occurs on the face, most often appearing on the white of the eye. It also occurs on the forehead, nose, cheek, periorbital region, and temple.
Eye shadow is a cosmetic applied primarily to the eyelids to attract attention to the wearer's eyes, making them stand out or look more attractive. Eye shadow can also be applied under the eyes, on the cheeks, or to brow bones.
Periorbital puffiness, also known as puffy eyes, or swelling around the eyes, is the appearance of swelling in the tissues around the eyes, called the orbits. It is almost exclusively caused by fluid buildup around the eyes, or periorbital edema. Minor puffiness usually detectable below the eyes only is often called eye bags. Such transient puffiness is distinct from the age related and gradual increase in the size of the fat pad lying below the lower eyelids which can also be colloquially referred to as eye bags.
Familial progressive hyperpigmentation is characterized by patches of hyperpigmentation, present at birth, which increase in size and number with age. This is a genetic disease, however the gene that accounts for this spotty darkening of the skin has yet to be discovered. Although rare, the congenital disease is most prevalent among populations originating from China.
Drug induced pigmentation may take on many different appearances, one of the most common being a change in the color, or pigmentation, of the skin.
Lelis syndrome is a genetic disorder, a rare condition with dermatological and dental findings characterized by the association of ectodermal dysplasia with acanthosis nigricans. Other clinical features may include palmoplantar hyperkeratosis, nail dystrophy, intellectual deficit, disturbances of skin pigmentation and hypodontia. Transmission is autosomal recessive.
Poikiloderma vasculare atrophicans (PVA), is a cutaneous condition characterized by hypo- or hyperpigmentation, telangiectasia and skin atrophy. Other names for the condition include prereticulotic poikiloderma and atrophic parapsoriasis. The condition was first described by pioneer American pediatrician Abraham Jacobi in 1906. PVA causes areas of affected skin to appear speckled red and inflamed, yellowish and/or brown, gray or grayish-black, with scaling and a thinness that may be described as "cigarette paper". On the surface of the skin, these areas may range in size from small patches, to plaques, to neoplasms.
Poikiloderma is a skin condition that consists of areas of hypopigmentation, hyperpigmentation, telangiectasias and atrophy. Poikiloderma of Civatte is most frequently seen on the chest or the neck, characterized by red colored pigment on the skin that is commonly associated with sun damage.
