Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete body coverage. Injury to the skin can trigger psoriatic skin changes at that spot, which is known as the Koebner phenomenon.
Epidermolytic ichthyosis (EI), is a rare and severe form of ichthyosis that affects around 1 in 300,000 people. It is caused by a genetic mutation, and thus cannot be completely cured without some form of gene therapy.
A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment.
Nevus is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa. The term originates from nævus, which is Latin for "birthmark"; however, a nevus can be either congenital or acquired. Common terms, including mole, birthmark, and beauty mark, are used to describe nevi, but these terms do not distinguish specific types of nevi from one another.
A dysplastic nevus or atypical mole is a nevus (mole) whose appearance is different from that of common moles. In 1992, the NIH recommended that the term "dysplastic nevus" be avoided in favor of the term "atypical mole". An atypical mole may also be referred to as an atypical melanocytic nevus, atypical nevus, B-K mole, Clark's nevus, dysplastic melanocytic nevus, or nevus with architectural disorder.
Lentigo maligna is where melanocyte cells have become malignant and grow continuously along the stratum basale of the skin, but have not invaded below the epidermis. Lentigo maligna is not the same as lentigo maligna melanoma, as detailed below. It typically progresses very slowly and can remain in a non-invasive form for years.
Blaschko's lines, also called the lines of Blaschko, are lines of normal cell development in the skin. These lines are only visible in those with a mosaic skin condition or in chimeras where different cell lines contain different genes. These lines may express different amounts of melanin, or become visible due to a differing susceptibility to disease. In such individuals, they can become apparent as whorls, patches, streaks or lines in a linear or segmental distribution over the skin. They follow a V shape over the back, S-shaped whirls over the chest and sides, and wavy shapes on the head. Not all mosaic skin conditions follow Blaschko's lines.
Angiokeratoma is a benign cutaneous lesion of capillaries, resulting in small marks of red to blue color and characterized by hyperkeratosis. Angiokeratoma corporis diffusum refers to Fabry's disease, but this is usually considered a distinct condition.
Cutis marmorata telangiectatica congenita is a rare congenital vascular disorder that usually manifests in affecting the blood vessels of the skin. The condition was first recognised and described in 1922 by Cato van Lohuizen, a Dutch pediatrician whose name was later adopted in the other common name used to describe the condition – Van Lohuizen Syndrome. CMTC is also used synonymously with congenital generalized phlebectasia, nevus vascularis reticularis, congenital phlebectasia, livedo telangiectatica, congenital livedo reticularis and Van Lohuizen syndrome.
Skin biopsy is a biopsy technique in which a skin lesion is removed to be sent to a pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin biopsies are also done by family physicians, internists, surgeons, and other specialties. However, performed incorrectly, and without appropriate clinical information, a pathologist's interpretation of a skin biopsy can be severely limited, and therefore doctors and patients may forgo traditional biopsy techniques and instead choose Mohs surgery.
Superficial lymphatic malformation is a congenital malformation of the superficial lymphatics, presenting as groups of deep-seated, vesicle-like papules resembling frog spawn, at birth or shortly thereafter. Lymphangioma circumscriptum is the most common congenital lymphatic malformation. It is a benign condition and treatment is not required if the person who has it does not have symptoms from it.
Ichthyosis hystrix is a group of rare skin disorders in the ichthyosis family of skin disorders characterized by massive hyperkeratosis with an appearance like spiny scales. This term is also used to refer to a type of epidermal nevi with extensive bilateral distribution.
Linear and whorled nevoid hypermelanosis is a disorder of pigmentation that develops within a few weeks of birth and progresses for one to two years before stabilizing. There is linear and whorled hyperpigmentation following the lines of Blaschko without preceding bullae or verrucous lesions. It is important to exclude other pigmentary disorders following the Blaschko lines before making a diagnosis of linear and whorled nevoid hypermelanosis. The differential diagnoses include incontinentia pigmenti, linear epidermal nevus, hypomelanosis of Ito and Goltz syndrome. Recently, a case of linear and whorled nevoid hypermelanosis was reported in a Malaysian Chinese girl.
Verruciform xanthoma is an uncommon benign lesion that has a verruciform (wart-like) appearance, but it may appear polypoid, papillomatous, or sessile. The verruciform was first described by Shafer in 1971 on the oral mucosa. Usually found on the oral mucosa of middle-aged persons, verruciform xanthomas have also been reported on the scrotum and penis of middle-aged to elderly Japanese males. While the most common site is the oral mucosa, lesions that occur elsewhere usually arise on the perineum or on the skin with some predisposing factor, such as lymphedema or an epidermal nevus.
Porokeratosis is a specific disorder of keratinization that is characterized histologically by the presence of a cornoid lamella, a thin column of closely stacked, parakeratotic cells extending through the stratum corneum with a thin or absent granular layer.
Linear verrucous epidermal nevus is a skin lesion characterized by a verrucous skin-colored, dirty-gray or brown papule. Generally, multiple papules present simultaneously, and coalesce to form a serpiginous plaque. When this nevus covers a diffuse or extensive portion of the body's surface area, it may be referred to as a systematized epidermal nevus, when it involved only one-half of the body it is called a nevus unius lateris.
Pseudomelanoma is a cutaneous condition in which melanotic skin lesions clinically resemble a superficial spreading melanoma at the site of a recent shave removal of a melanocytic nevus.
Supernumerary nipples–uropathies–Becker's nevus syndrome is a skin condition that may be associated with genitourinary tract abnormalities. Supernumerary nipples, also referred to as polythelia or accessory nipples, is a pigmented lesion of the skin that is present at birth. This pigmentation usually occurs along the milk lines, which are the precursors to breast and nipple development. Clinically, this congenital condition is generally considered benign, but some studies have suggested there may be an association with kidney diseases and cancers of the urogenital system.
Stasis papillomatosis is a disease characterized by chronic congestion of the extremities, with blood circulation interrupted in a specific area of the body. A consequence of this congestion and inflammation is long-term lymphatic obstruction. It is also typically characterized by the appearance of numerous papules. Injuries can range from small to large plates composed of brown or pink, smooth or hyperkeratotic papules. The most typical areas where injuries occur are the back of the feet, the toes, the legs, and the area around a venous ulcer formed in the extremities, although the latter is the rarest of all. These injuries include pachydermia, lymphedema, lymphomastic verrucosis and elephantosis verrucosa. The disease can be either localized or generalized; the localized form makes up 78% of cases. Treatment includes surgical and pharmaceutical intervention; indications for partial removal include advanced fibrotic lymphedema and elephantiasis. Despite the existence of these treatments, chronic venous edema, which is a derivation of stasis papillomatosis, is only partially reversible. The skin is also affected and its partial removal may mean that the skin and the subcutaneous tissue are excised. A side effect of the procedure is the destruction of existing cutaneous lymphatic vessels. It also risks papillomatosis, skin necrosis and edema exacerbation.
