List of Skin Diseases and Conditions

Introduction

Human skin weighs on average four kilograms and covers an area equal to around two square metres. Human skin is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue.

Main Item

The diagnosis of a particular skin condition is performed by gathering all pertinent information regarding the presenting skin lesion(s) or condition, duration (acute or chronic), arrangement (solitary, generalized, annular, linear), morphology (macules, papules, vesicles), location (such as arms, head, legs), symptoms (pruritus, pain), and color (red, white, yellow, blue, brown, black etc.)

Illustration shows the three primary layers of human skin; epidermis, dermis, and hypodermis.

Conditions of the human integumentary system constitute a broad spectrum of diseases, also known as dermatoses, as well as many nonpathologic states:

• Abnormalities of dermal fibrous and elastic tissue are caused by problems in the regulation of collagen synthesis or degradation.
• Acneiform eruptions are caused by changes in the pilosebaceous unit.
• Angioedema, which can occur alone or with urticaria, is characterized by a well-defined, edematous swelling that involves:
  • Subcutaneous tissues
  • Abdominal organs
  • Upper airway
• Atopic dermatitis is a chronic dermatitis associated with a hereditary tendency to develop allergies to food and inhalant substances.
• Autoinflammatory syndromes are a group of inherited disorders characterized by bouts of inflammatory skin lesions and periodic fevers.
• Bacterium-related cutaneous conditions often have distinct morphologic characteristics that may be an indication of a generalized systemic process or simply an isolated superficial infection.
• Chronic blistering cutaneous conditions have a prolonged course and present with vesicles and bullae.
• Conditions of the mucous membranes involve the moist linings of the eyes, nose, mouth, genitals, and anus.
• Conditions of the skin appendages are those affecting the glands of the skin, hair, nails, and arrector pili muscles.
• Conditions of the subcutaneous fat are those affecting the layer of adipose tissue that lies between the dermis and underlying fascia.
• Connective tissue diseases are caused by a complex array of autoimmune responses that target or affect collagen or ground substance.
• Contact dermatitis is caused by certain substances coming in contact with the skin.
• Cutaneous congenital anomalies are a diverse group of disorders that result from faulty morphogenesis, the biological process that forms the shape of a human body.
• Dermal and subcutaneous growths result from:
• Reactive or neoplastic proliferation of cellular components of the dermis
• Subcutaneous tissue
• Neoplasms invading or aberrantly present in the dermis.
• Dermatitis is a general term for inflammation of the skin.
• Disturbances of human pigmentation, either loss or reduction, may be related to:
  • Loss of melanocytes
  • Inability of melanocytes to produce melanin or transport melanosomes correctly
• Drug eruptions are adverse drug reactions that present with cutaneous manifestations.
• Eczema refers to a broad range of conditions that begin as spongiotic dermatitis and may progress to a lichenified stage.
• Endocrine conditions often present with cutaneous findings as the skin interacts with the endocrine system in many ways.
• Eosinophilic cutaneous conditions encompass a wide variety of diseases that are characterized histologically by the presence of eosinophils in the inflammatory infiltrate, or evidence of eosinophil degranulation.
• Epidermal nevi, neoplasms, and cysts are skin lesions that develop from the epidermal layer of the skin.
• Erythemas are reactive skin conditions in which there is blanchable redness.
• Genodermatoses are inherited genetic skin conditions often grouped into three categories:
  • Chromosomal
  • Single gene
  • Polygenetic
• Infection-related cutaneous conditions may be caused by:
  • Bacteria
  • Fungi
  • Yeast
  • Viruses
  • Parasites
• Ionizing radiation-induced cutaneous conditions result from exposure to ionizing radiation.
• Lichenoid eruptions are dermatoses related to the unique, common inflammatory disorder lichen planus, which affects the skin, mucous membranes, nails, and hair.
• Lymphoid-related cutaneous conditions are a group of disorders characterized by collections of lymphocyte cells within the skin.
• Melanocytic nevi and neoplasms are caused by either a proliferation of melanocytes, or nevus cells, a form of melanocyte that lack dendritic processes.
• Melanoma is a malignant proliferation of melanocytes and the most aggressive type of skin cancer.
• Monocyte- and macrophage-related cutaneous conditions are characterized histologically by infiltration of the skin by monocyte or macrophage cells, often divided into several categories, including:
  • Granulomatous disease
  • Histiocytoses
  • Sarcoidosis.
• Mucinoses are a group of conditions caused by dermal fibroblasts producing abnormally large amounts of mucopolysaccharides.
• Mycobacterium-related cutaneous conditions are caused by Mycobacterium infections.
• Mycosis-related cutaneous conditions are caused by fungi or yeasts, and may present as either a superficial or deep infection of the skin, hair, or nails.
• Neurocutaneous conditions are due organic nervous system disease or are psychiatric in etiology.
• Noninfectious immunodeficiency-related cutaneous conditions are caused by T-cell or B-cell dysfunction.
• Nutrition-related cutaneous conditions are caused by malnutrition due to an improper or inadequate diet.
• Palmoplantar keratodermas are a diverse group of hereditary and acquired keratodermas in which there is hyperkeratosis of the skin of the palms and soles.
• Papulosquamous hyperkeratotic cutaneous conditions are those that present with papules and scales caused by a thickening of the stratum corneum.
• Parasitic infestations, stings, and bites in humans are caused by several groups of organisms belonging to the following phyla:
  • Annelida
  • Arthropoda
  • Bryozoa
  • Chordata
  • Cnidaria
  • Cyanobacteria
  • Echinodermata
  • Nemathelminthes
  • Platyhelminthes
  • Protozoa
• Pregnancy-related cutaneous conditions are a group of skin changes observed during pregnancy.
• Pruritus, commonly known as itchiness, is a sensation exclusive to the skin, and characteristic of many skin conditions.
• Psoriasis is a common, chronic, and recurrent inflammatory disease of the skin characterized by circumscribed, erythematous, dry, scaling plaques.
• Pustular dermatitis is an inflammation of the skin that presents with pustular lesions.
• Reactive neutrophilic cutaneous conditions constitute a spectrum of disease mediated by neutrophils, and typically associated with underlying diseases, such as:
  • Inflammatory bowel disease
  • Hematologic malignancy.
• Recalcitrant palmoplantar eruptions are skin conditions of the palms and soles which are resistant to treatment.
• Seborrheic dermatitis is a chronic, superficial, inflammatory disease characterized by scaling on an erythematous base.
• Skin conditions resulting from errors in metabolism are caused by enzymatic defects that lead to an accumulation or deficiency of various cellular components, including, but not limited to:
• Amino acids
• Carbohydrates
• Lipids
• Skin conditions resulting from physical factors occur from a number of causes, including, but not limited to:
  • Hot and cold temperatures
  • Friction
  • Moisture
• Urticaria is a vascular reaction of the skin characterized by the appearance of wheals, which are firm, elevated swelling of the skin.
• Vascular-related cutaneous conditions result from dysfunction of the blood or blood vessels in the dermis, or lymphatics in the subcutaneous tissues.
• Virus-related cutaneous conditions are caused by two main groups of viruses - DNA and RNA types - both of which are obligatory intracellular parasites.

List of Skin Conditions and Diseases

Other interesting facts regarding skin can be found on our human body facts web page.