{
  "name": "Dermatology glossary",
  "description": "Plain-English definitions of the vocabulary used in a dermatology consultation, each tied to the layer of skin it belongs to where that applies.",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Dermatology glossary by dermatology-clinic.net, licensed CC BY 4.0. https://dermatology-clinic.net/open-data/dermatology-glossary/",
  "source": "https://dermatology-clinic.net/glossary/",
  "count": 26,
  "terms": [
    {
      "term": "Biopsy",
      "slug": "biopsy",
      "definition": "A biopsy is the removal of a small sample of tissue so it can be examined under a microscope. In dermatology the sample is skin, and it is taken when appearance alone cannot settle what is happening.",
      "set": "dermatology-terms",
      "layer": "dermis",
      "url": "https://dermatology-clinic.net/glossary/biopsy/",
      "updated": "2026-08-03"
    },
    {
      "term": "Collagen",
      "slug": "collagen",
      "definition": "Collagen is the structural protein that makes up most of the dermis. Arranged in fibres, it gives skin its tensile strength and resistance to tearing, and it works alongside elastin, which supplies the ability to return to shape after stretching.",
      "set": "skin-anatomy",
      "layer": "dermis",
      "url": "https://dermatology-clinic.net/glossary/collagen/",
      "updated": "2026-08-03"
    },
    {
      "term": "Comedone",
      "slug": "comedone",
      "definition": "A comedone is a blocked hair follicle without significant inflammation. Open comedones reach the surface and darken through oxidation, giving blackheads their colour, while closed comedones remain under a thin covering of skin as small pale bumps.",
      "set": "dermatology-terms",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/comedone/",
      "updated": "2026-08-03"
    },
    {
      "term": "Dermatophyte",
      "slug": "dermatophyte",
      "definition": "A dermatophyte is a fungus that digests keratin, allowing it to live in the outermost layer of the skin and in hair and nails. Dermatophytes cause the common superficial fungal infections grouped under the clinical prefix tinea.",
      "set": "dermatology-terms",
      "layer": "stratum-corneum",
      "url": "https://dermatology-clinic.net/glossary/dermatophyte/",
      "updated": "2026-08-03"
    },
    {
      "term": "Dermatoscope",
      "slug": "dermatoscope",
      "definition": "A dermatoscope is a handheld magnifier with its own light source, held against the skin to examine it. It reveals patterns of pigment and small blood vessels below the surface that cannot be seen with the naked eye.",
      "set": "dermatology-terms",
      "layer": "junction",
      "url": "https://dermatology-clinic.net/glossary/dermatoscope/",
      "updated": "2026-08-03"
    },
    {
      "term": "Dermis",
      "slug": "dermis",
      "definition": "The dermis is the layer beneath the epidermis, considerably thicker than it, and it contains the blood vessels, nerves, sweat glands, hair follicles and the collagen and elastin that give skin its strength and elasticity.",
      "set": "skin-anatomy",
      "layer": "dermis",
      "url": "https://dermatology-clinic.net/glossary/dermis/",
      "updated": "2026-08-03"
    },
    {
      "term": "Dermo-epidermal junction",
      "slug": "dermo-epidermal-junction",
      "definition": "The dermo-epidermal junction is the boundary between the epidermis and the dermis. Far from flat, it is folded into interlocking ridges that increase the contact area between the two layers and anchor them to each other.",
      "set": "skin-anatomy",
      "layer": "junction",
      "url": "https://dermatology-clinic.net/glossary/dermo-epidermal-junction/",
      "updated": "2026-08-03"
    },
    {
      "term": "Epidermis",
      "slug": "epidermis",
      "definition": "The epidermis is the outer layer of the skin, sitting above the dermis and containing no blood vessels of its own. It is built mainly from keratinocytes, which are produced at its base, mature as they rise, and are eventually shed from the surface.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/epidermis/",
      "updated": "2026-08-03"
    },
    {
      "term": "Erythema",
      "slug": "erythema",
      "definition": "Erythema means redness of the skin caused by increased blood flow in the small vessels of the dermis. It is a description of appearance rather than a diagnosis, and it is one of the most frequently used words in dermatology.",
      "set": "dermatology-terms",
      "layer": "dermis",
      "url": "https://dermatology-clinic.net/glossary/erythema/",
      "updated": "2026-08-03"
    },
    {
      "term": "Excoriation",
      "slug": "excoriation",
      "definition": "An excoriation is a break in the skin produced by scratching or rubbing rather than by the underlying condition itself. Clinicians distinguish it from primary changes because it records what has been done to the skin, not what is happening in it.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/excoriation/",
      "updated": "2026-08-03"
    },
    {
      "term": "Hair follicle",
      "slug": "hair-follicle",
      "definition": "A hair follicle is the structure in the skin from which a hair grows. It extends from an opening at the surface down into the dermis, and it is usually paired with a sebaceous gland, the two together forming the pilosebaceous unit.",
      "set": "skin-anatomy",
      "layer": "dermis",
      "url": "https://dermatology-clinic.net/glossary/hair-follicle/",
      "updated": "2026-08-03"
    },
    {
      "term": "Hypodermis",
      "slug": "hypodermis",
      "definition": "The hypodermis is the layer beneath the dermis, made largely of fat and connective tissue. Also called the subcutis or subcutaneous layer, it cushions and insulates, and it anchors the skin to the structures underneath.",
      "set": "skin-anatomy",
      "layer": "hypodermis",
      "url": "https://dermatology-clinic.net/glossary/hypodermis/",
      "updated": "2026-08-03"
    },
    {
      "term": "Keratinocyte",
      "slug": "keratinocyte",
      "definition": "A keratinocyte is the main cell type of the epidermis. Keratinocytes are produced at its base, fill with keratin as they rise towards the surface, flatten, lose their nuclei, and are eventually shed as part of the outermost layer.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/keratinocyte/",
      "updated": "2026-08-03"
    },
    {
      "term": "Lesion",
      "slug": "lesion",
      "definition": "A lesion is any localised area of altered skin. The word is deliberately neutral: it describes that something is there and where it is, without implying anything about what it is or how serious it might be.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/lesion/",
      "updated": "2026-08-03"
    },
    {
      "term": "Macule",
      "slug": "macule",
      "definition": "A macule is a flat area of skin that differs in colour from the skin around it, without being raised or depressed. Running a finger over one detects nothing: the change is in colour alone, which is what distinguishes it from a papule.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/macule/",
      "updated": "2026-08-03"
    },
    {
      "term": "Melanin",
      "slug": "melanin",
      "definition": "Melanin is the pigment that gives skin, hair and eyes their colour. Made by melanocytes and passed to surrounding cells, it absorbs ultraviolet radiation, positioning itself over the cell nucleus where it shields the genetic material inside.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/melanin/",
      "updated": "2026-08-03"
    },
    {
      "term": "Melanocyte",
      "slug": "melanocyte",
      "definition": "A melanocyte is a cell in the lower epidermis that produces melanin, the pigment giving skin, hair and eyes their colour. Each melanocyte supplies pigment to a group of neighbouring cells, which carry it towards the surface.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/melanocyte/",
      "updated": "2026-08-03"
    },
    {
      "term": "Naevus",
      "slug": "naevus",
      "definition": "A naevus, plural naevi, is the clinical term for a mole: a cluster of pigment-producing cells in the skin. Qualifiers describe where the cluster sits and how ordinary it looks, and none of them is a diagnosis in itself.",
      "set": "dermatology-terms",
      "layer": "junction",
      "url": "https://dermatology-clinic.net/glossary/naevus/",
      "updated": "2026-08-03"
    },
    {
      "term": "Papule",
      "slug": "papule",
      "definition": "A papule is a small raised area of skin, solid rather than fluid-filled, that can be felt as well as seen. It is distinguished from a macule, which is flat, from a pustule, which contains pus, and from a nodule, which is larger and deeper.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/papule/",
      "updated": "2026-08-03"
    },
    {
      "term": "Plaque",
      "slug": "plaque",
      "definition": "A plaque is a raised area of skin that is broad relative to its height, with a flat or slightly domed top. The word describes shape alone, and it is used most often when a condition produces patches larger than a papule.",
      "set": "dermatology-terms",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/plaque/",
      "updated": "2026-08-03"
    },
    {
      "term": "Pruritus",
      "slug": "pruritus",
      "definition": "Pruritus is the clinical term for itch: the sensation that provokes scratching. It is carried by its own nerve pathways rather than being a mild form of pain, and it can occur with visible skin changes or without any at all.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/pruritus/",
      "updated": "2026-08-03"
    },
    {
      "term": "Pustule",
      "slug": "pustule",
      "definition": "A pustule is a small raised lesion containing pus, a mixture of immune cells and fluid. Despite the association, its presence does not establish that an infection is responsible: several non-infectious conditions produce pustules.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/pustule/",
      "updated": "2026-08-03"
    },
    {
      "term": "Scale",
      "slug": "scale",
      "definition": "Scale is visible flaking of the outermost layer of the skin, produced when cells are shed in clumps rather than individually. Its character differs between conditions, and clinicians describe how it looks as well as noting that it is present.",
      "set": "dermatology-terms",
      "layer": "",
      "url": "https://dermatology-clinic.net/glossary/scale/",
      "updated": "2026-08-03"
    },
    {
      "term": "Sebaceous gland",
      "slug": "sebaceous-gland",
      "definition": "A sebaceous gland is a small gland attached to a hair follicle that produces sebum, an oily substance released into the follicle and onto the skin surface. Together the gland and follicle form what is called the pilosebaceous unit.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/sebaceous-gland/",
      "updated": "2026-08-03"
    },
    {
      "term": "Sebum",
      "slug": "sebum",
      "definition": "Sebum is the oily substance produced by sebaceous glands and released into hair follicles, from where it reaches the skin surface. It contributes to the film covering the skin and to the environment that organisms living on skin encounter.",
      "set": "skin-anatomy",
      "layer": "epidermis",
      "url": "https://dermatology-clinic.net/glossary/sebum/",
      "updated": "2026-08-03"
    },
    {
      "term": "Stratum corneum",
      "slug": "stratum-corneum",
      "definition": "The stratum corneum is the outermost part of the epidermis, made of flattened dead cells filled with keratin and embedded in a lipid matrix. It forms the skin's barrier, holding water in and keeping most external substances out.",
      "set": "skin-anatomy",
      "layer": "stratum-corneum",
      "url": "https://dermatology-clinic.net/glossary/stratum-corneum/",
      "updated": "2026-08-03"
    }
  ]
}