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.
Lichen planus (LP) is a chronic inflammatory and autoimmune disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, but is named for its appearance. It is characterized by polygonal, flat-topped, violaceous papules and plaques with overlying, reticulated, fine white scale, commonly affecting dorsal hands, flexural wrists and forearms, trunk, anterior lower legs and oral mucosa. The hue may be gray-brown in people with darker skin. Although there is a broad clinical range of LP manifestations, the skin and oral cavity remain as the major sites of involvement. The cause is unknown, but it is thought to be the result of an autoimmune process with an unknown initial trigger. There is no cure, but many different medications and procedures have been used in efforts to control the symptoms.
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.
Granuloma annulare (GA) is a rare, sometimes chronic skin condition which presents as reddish bumps on the skin arranged in a circle or ring. It can initially occur at any age, though two-thirds of patients are under 30 years old, and it is seen most often in children and young adults. Females are two times as likely to have it as males.
Erythema annulare centrifugum (EAC), is a descriptive term for a class of skin lesion presenting redness (erythema) in a ring form (anulare) that spreads from a center (centrifugum). It was first described by Darier in 1916. Many different terms have been used to classify these types of lesions and it is still controversial on what exactly defines EAC. Some of the types include annular erythema, erythema perstans, erythema gyratum perstans, erythema gyratum repens, darier erythema and erythema figuratum perstans.
Papular mucinosis is a rare skin disease. Localized and disseminated cases are called papular mucinosis or lichen myxedematosus while generalized, confluent papular forms with sclerosis are called scleromyxedema. Frequently, all three forms are regarded as papular mucinosis. However, some authors restrict it to only mild cases. Another form, acral persistent papular mucinosis is regarded as a separate entity.
Lichen nitidus is a chronic inflammatory disease of unknown cause characterized by 1–2 mm, discrete and uniform, shiny, flat-topped, pale flesh-colored or reddish-brown papules that may appear as hypopigmented against dark skin. Occasionally, minimal scaling is present or can be induced by rubbing the surface of the papules. The disease usually affects children and young adults and is painless and usually nonpruritic, although protracted itching may occur in some cases. It is sometimes referred to by dermatologists as "mini lichen planus".
Cutaneous endometriosis is characterized by the appearance of papules at the umbilicus or in lower abdominal scars after gynecologic surgery in middle-aged women. The size averages to 2 cm in diameter. Its colour ranges from blue to violet, brown or skin-coloured.
Solitary mastocytoma, also known as cutaneous mastocytoma, may be present at birth or may develop during the first weeks of life, originating as a brown macule that urticates on stroking. Solitary mastocytoma is a round, erythematous, indurated lesion measuring 1-5 cm in diameter. It can be mildly itchy or asymptomatic and develops over time. Predilection is the head and neck, followed by the trunk, extremities, and flexural areas.
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.
Annular erythema of infancy(AEI) consists of self-limited eruptions of erythematous, annular to polycyclic patches and plaques. It is an idiopathic figurate erythema. Over several days, a single lesion disappears without leaving behind any scale or hyperpigmentation. Mostly affecting the trunk, face, and extremities, this rash has no symptoms. The diagnosis of AEI is made through a combination of histopathologic and clinical examinations. The disease first manifests in infancy, and if treatment is not received, the periodic eruptions usually stop after the first year of life.
Acral persistent papular mucinosis (APPM) is a rare form of lichen myxedematosus. It is characterized by small papules on the backs of the hands, wrists, and extensor aspects of the distal forearms, with no further clinical or laboratory indications. Lesions tend to persist and may grow in number gradually. Because there are no symptoms, treatment is rarely required.
Majocchi's granuloma is a skin condition characterized by deep, pustular plaques, and is a form of tinea corporis. It is a localized form of fungal folliculitis. Lesions often have a pink and scaly central component with pustules or folliculocentric papules at the periphery. The name comes from Domenico Majocchi, who discovered the disorder in 1883. Majocchi was a professor of dermatology at the University of Parma and later the University of Bologna. This disease is most commonly caused by filamentous fungi in the genus Trichophyton.
Generalized granuloma annulare is a skin condition of unknown cause, tending to affect women in the fifth and sixth decades, presenting as a diffuse but symmetrical, papular or annular eruption of more than ten skin lesions, and often hundreds.
Actinic granuloma (AG) was first described by O'Brien in 1975 as a rare granulomatous disease. Lesions appear on sun-exposed areas, usually on the face, neck, and scalp, with a slight preference for middle-aged women. They are typically asymptomatic, single or multiple, annular or polycyclic lesions measuring up to 6 cm in diameter, with slow centrifugal expansion, an erythematous elevated edge, and a hypopigmented, atrophic center.
Granuloma multiforme is a cutaneous condition most commonly seen in central Africa, and rarely elsewhere, characterized by skin lesions that are on the upper trunk and arms in sun-exposed areas. It may be confused with tuberculoid leprosy, with which it has clinical similarities. The condition was first noted by Gosset in the 1940s, but it was not until 1964 that Leiker coined the term to describe "a disease resembling leprosy" in his study in Nigeria.
Cutaneous lymphoid hyperplasia refers to a groups of benign cutaneous disorders characterized by collections of lymphocytes, macrophages, and dendritic cells in the skin. Conditions included in this groups are:
An eccrine nevus is an extremely rare cutaneous condition that, histologically, is characterized by an increase in size or number of eccrine secretory coils. Hyperhidrosis is the most common symptom. It can present as discoloured nodules, papules, or plaques. Eccrine nevus mostly affects the extremities. Eccrine nevus are diagnosed based of histology. Treatment includes surgical excision or topical medications.
Cutaneous lupus mucinosis, also known as papular and nodular mucinosis in lupus erythematosus, papular and nodular mucinosis of Gold, and papulonodular mucinosis in lupus erythematosus, is a cutaneous condition characterized by lesions that present as asymptomatic skin-colored, at times reddish, 0.5–2 cm papules and nodules.
