Becker's nevus is a skin disorder predominantly affecting males. The nevus can be present at birth, but more often shows up around puberty. It generally first appears as an irregular pigmentation on the torso or upper arm, and gradually enlarges irregularly, becoming thickened and often hairy (hypertrichosis). The nevus is due to an overgrowth of the epidermis, pigment cells (melanocytes), and hair follicles. This form of nevus was first documented in 1948 by American dermatologist Samuel William Becker (1894–1964).
Blaschko's lines, also called the lines of Blaschko, named after Alfred Blaschko, are lines of normal cell development in the skin. These lines are invisible under normal conditions. They become apparent when some diseases of the skin or mucosa manifest themselves according to these patterns. They follow a "V" shape over the back, "S" shaped whirls over the chest and sides, and wavy shapes on the head.
Nevus of Ota is a blue hyperpigmentation that occurs on the face, most often appearing on the white of the eye. It was first reported by Dr. M.T. Ota of Japan in 1939.
Blue nevus is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.
Phakomatosis pigmentovascularis is a rare neurocutanous condition where there is coexistence of a capillary malformation with various melanocytic lesions, including dermal melanocytosis, nevus spilus, and nevus of Ota.
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.
Nevus sebaceus or sebaceous nevus is a congenital, hairless plaque that typically occurs on the face or scalp. Such nevi are present at birth, or early childhood, affecting males and females of all races equally. The condition is named for an overgrowth of sebaceous glands in the area of the nevus.
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.
Epidermal nevus syndrome is a rare disease that was first described in 1968 and consists of extensive epidermal nevi with abnormalities of the central nervous system (CNS), skeleton, skin, cardiovascular system, genitourinary system and eyes. However, since the syndrome's first description, a broader concept for the "epidermal nevus" syndrome has been proposed, with at least six types being described:
Schimmelpenning syndrome is a neurocutaneous condition characterized by one or more sebaceous nevi, usually appearing on the face or scalp, associated with anomalies of the central nervous system, ocular system, skeletal system, cardiovascular system, and genitourinary system.
Nevus comedonicus syndrome is a skin condition characterized by a nevus comedonicus associated with cataracts, scoliosis, and neurologic abnormalities.
Pigmented hairy epidermal nevus syndrome is a cutaneous condition characterized by a Becker nevus, ipsilateral hypoplasia of the breast, and skeletal defects such as scoliosis.
Phakomatosis pigmentokeratotica is a rare neurocutanous condition characterized by the combination of an organoid sebaceous nevus and speckled lentiginous nevus. It is an unusual variant of epidermal naevus syndrome. It was first described by Happle et al. It is often associated with neurological or skeletal anomalies such as hemiatrophy, dysaesthesia and hyperhidrosis in a segmental pattern, mild mental retardation, seizures, deafness, ptosis and strabismus.
Inflammatory Linear Verrucous Epidermal Nevus (ILVEN) is a rare disease of the skin that presents as multiple, discrete, red papules that tend to coalesce into linear plaques that follow the Lines of Blaschko. The plaques can be slightly warty (psoriaform) or scaly (eczema-like). ILVEN is caused by somatic mutations that result in genetic mosaicism. There is no cure, but different medical treatments can alleviate the symptoms.
Nevus unius lateris is a cutaneous condition, an epidermal nevus in which the skin lesions are distributed on one-half of the body.
Linear Darier disease is a cutaneous condition identical to the generalized form of Darier's disease. "Acantholytic dyskeratotic epidermal nevus" is probably the same disorder.
A urethral caruncle is a benign cutaneous condition characterized by distal urethral lesions that are most commonly found in post-menopausal women. They appear red, and can be various sizes. They can have the appearance of a tumor. These epidermal growths are found around the posterior portion of the urethral meatus. They can bleed and occasionally cause dysuria and dyspareunia. The caruncles can be removed by surgery, electric cauterization and then with suture repair. Pathology studies are necessary to distinguish carcinoma of the urethra from urethral caruncles. Caruncles can grow back in some instances. Urethral caruncles can accompany the skin changes related to lowered estrogen levels. They can become a source of chronic hematuria, infection, and urethritis.
Verrucous perforating collagenoma is a very rare skin disorder which presents with verrucous papules with a transepidermal elimination of collagen.
