Acne Glossary

A Glossary of Acne Related Terms

Acne Glossary in Alphabetical Order:
A | B | C | D | E | F | G | H | I | J | K | L | M
N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Acne Glossary : A

Abscess: A collection of neutrophils in the epidermis, hair follicles, sweat glands, dermis or subcutaneous tissue.

Acne: Acne is the commonest skin disease. Acne is actually a disease of the hair unit of the skin involving the oil producing sebaceous glands

Acne conglobata: Severe scarring type of nodulo-cystic acne in which involved areas contain a mixture of double comedones, papules, pustules, communicating cysts, abscesses, and draining sinus tracts.

Acne Scars: Acne scars are caused by healing of inflamed acne lesions. Skin repairs itself after any injury, including inflammation, by generating new collagen underneath. This deposition of new connective tissue causes acne scar . The main cause of acne scar is uncontrolled disease activity causing continuous inflammatory response within the dermis.

Alternative Medicine: Systems of medicine other than the modern medicine. Most of them have no scientific basis.

Androgen hormones: These are hormones produced by the sex hormone releasing glands, like testes (males) and ovaries (females) and the adrenal glands. The main circulating androgens are testosterone, dihydrotestosterone and dehydroepiandrosterone sulfate (DHEAS). Increased androgen secretion by these glands at the time of puberty induce sebaceous gland activity and the development of acne.

Atopic dermatitis (Syn. Atopic eczema): An allergic skin disorder that is characterized by itching, scaling, thickening of the skin, and usually located on the face, elbows, knees, and arms. An immune mediated illness, which usually starts in early childhood.

Atrophy, epidermal: Thinning of the epidermis due to decrease in size of epidermal cells. Rete ridges are flattened and dermal papillae are obliterated. Seen in lichen sclerosus et atrophicus, discoid lupus erythematosus etc. Also seen in skin treated with topical corticosteroids.

Autoimmunity (Syn.autoallergy): An allergic immune response to'self' tissues, a mistake on part of the body's immune system which confuses the body's own tissues as 'foreign' and organize defensive actions through the production of antibodies. Such an immune response may have pathological effects and lead to 'autoimmune' diseases.

Autoimmune disease: An illness that occurs when the body cells or tissues are attacked by its own immune system. Normally, the immune system recognize and destroy invaders(antigens) of the body.. These include infectious agents . Patients with autoimmune diseases have circulating auto-antibodies that are formed against their own body elements.

Back to Top

Acne Glossary : B

Basal Cell Layer: The lowest germinative layer of the epidermis. Basal cells are responsible for producing the new squamous cells or keratinocytes of the epidermis. This is an ongoing process.

Biofeedback: A relaxation technique in which people are taught to control a few selected bodily functions like sweating, blood pressure or heart rate, which are usually considered involuntary. Feed back suggestions are given, and these act through the autonomic nervous system to produce the desired effects.

Biopsy: The removal of a small piece of body tissue for examination under a microscope for the purpose of studying the histo-pathological changes in a disease.

Blackhead: Blackhead is an open comedone, when the black horny plug blocking the hair orifice becomes visible due to the dilatation of the opening.

Blister (Vesicle/Bulla): A cavity filled with fluid. It may contain tissue fluid, plasma or blood and is often associated with inflammatory cells.

Boil (syn. Furuncle): Painful, swollen lesions that form around hair follicles due to inflammation and infection.

Bulla (Syn.Blister): Localized, fluid collection, more than 0.5 cm in diameter, a large vesicle.

Back to Top

Acne Glossary : C

Candidiasis: A skin and mucous membrane infection caused by a yeast known as Candida albicans that can occur in the skin folds, navel, vagina, penis, mouth, and nail beds. Usually seen in people with reduced immune status like diabetes, treatment with cortico steroids, cancers, HIV infection etc.

Cell: A cell contains all of the genetic information it takes to make a living being. The cell is the basic unit of the tissues which make up the organs of the body. The cell contains a central nucleus and surrounding cytoplasm. The cell nucleus contains 23 pairs of chromosomes (one half of each pair is inherited from each parent) which carries the genetic information.

Chemotaxis: Migration of cells from one place to other, usually due to a difference in concentration or chemical gradient .

Chromosome: Chromosomes carry the genetic information of an individual. It is seen inside the nucleus of the cell and consists of double strands of DNA (deoxy-ribonucleic acid). There are thought to be more than 35,000 distinct genes in human chromosomes, each responsible for different characteristics and disease susceptibility.

Chronic: A condition that has a long course of illness dotted with waxing and waning. Some are progressively worsening types. Most of these diseases have no cure.

Clobetasol propionate: It is a super potent cortico steroid used in allergic and inflammatory skin conditions. Due to potential side effects, these should be used only under medical supervision. This is a very common cause for steroid acne on the face and the body.

Closed Comedone: Closed comedone or the white head occurs when the comedonal plug blocks the small hair orifice from below and pushes it out as a skin colored small papule.

Comedone: A comedone or comedo is a collection of sebum and keratin inside the hair follicle. This is the primary lesion of acne. There are 2 types of comedones the open comedone or closed comedone.

Cornified Cells: Cells inside the hair infundibulum become cornified due to increased keratinization of the follicular epithelium due to the effect of the action of the androgens. This causes a process known as retention hyperkeratosis and is the basis for the formation of the comedonal plug which blocks the hair opening in acne.

Corticosteroid: A synthetic hormone similar to that produced naturally by the adrenal glands. Used in allergic and inflammatory conditions. Available in both topical, oral and injectable preparations. Different molecules have different strengths. Has to be used under medical supervision only.

Crust (Syn. Scab.): Collections of inflammatory cells, serum and/or fibrin and keratotic material usually covering an erosion or ulcer.

Cyst: Cyst is a deep seated nodule that contains semisolid material or fluid. Cysts are seen in acne, sebaceous cysts, epidermoid cyst, pilar cyst etc.

Cytokine: These are specialized proteins which are chemical messengers used by our immune system to communicate messages between cells.

Back to Top

Acne Glossary : D

Deoxyribonucleic acid (DNA): The double helical structure within the nucleus of cells which carries the genetic or hereditary information from the parents.

Depression: Recurring and persistent feelings of hopelessness, helplessness, despair, and, in some cases, thoughts of suicide.

Dermatologist: A skin care specialist physician who specializes in the diagnosis and treatment of conditions that affect the skin, hair, nails, and mucous membranes. The dermatologists have to study further 2-3 years after their basic medical degree to earn their postgraduate diploma or degree in the subject.

Dermatitis: A number of skin conditions characterized by inflammation of the skin. The cause may be either allergic or infective.

Dermis: The middle layer of skin (between the epidermis and subcutaneous fat) which is made up of blood vessels, nerve endings, lymph vessels, hair follicles, sebaceous glands, sweat glands, and connective tissue. Connective tissue of dermis consisting of collagen, elastic tissue and ground substance formed by fibroblasts , provides the strength of the skin. The dermis is made up of papillary, adventitial (around the appendages and vessels) and reticular dermis. The papillary and adventitial dermis consists of fine fibers, which are loose. The reticular dermis, in contrast, is deeper to the papillary dermis and is composed of much coarser thick eosinophilic collagen fibers .

Back to Top

Acne Glossary : E

Eczema (Syn. Dermatitis): Eczema is derived from the Greek meaning "a boiling out". It consists of a group of inflammatory diseases of the skin, characterized by oozing, crusting, and/or scaling. Divided into acute, sub acute and chronic variants.

Edema: Swelling of a part of body due to the accumulation of fluid either inside the cells or in between (intercellular space) the cells.

Emollient: A topical application prepared of fat or oil that holds the moisture inside and softens and soothes the skin.

Epidermis: The superficial layers of the skin, consisting of an outer, dead layer and a deeper, living, cellular layers. Divided into 5 layers: Basal, spinous, granular, lucid, and stratum corneum or horny layer. The epidermis is composed of four types of cells, the majority being keratinocytes and the minority melanocytes, Langerhans cells and neuro-endocrine cells (Merkel cells). The keratinocytes undergo characteristic changes during their transit through the epidermis from the undifferentiated basal cells to fully differentiated cornified cells. They are arranged in five layers : basal cell layer (stratum basalis), squamous or prickle cell layer (stratum spinosum), granular cell layer (stratum granulosum), stratum lucidum and horny cell layer (stratum corneum). The undersurface of the epidermis undulates with downward extensions called rete ridges or rete pegs. They interdigitate with cone-shaped upward projections of the dermis called dermal papillae.

Eruptions: Lesions on the skin that are usually red, raised, and easily visible.

Erythema: Erythema is redness of the skin caused by increased blood flow to the capillaries. There are many causes and manifestations of erythema, including photosensitivity, erythema multiforme, and erythema nodusum.

Erythematous: Redness.

Excoriation : An abraded area of the skin usually caused by scratching.

Back to Top

Acne Glossary : F

FDA: Food and Drug Administration. One of its responsibilities includes making sure drugs are safe and efficacious before being cleared for sale to the public.

Fish oils: Oils derived from fish that are rich in omega-3, a polyunsaturated fat often missing from many people�s diets. Some studies show that these are beneficial in acne.

Folliculitis: An inflammation of the hair follicles due to an infection or irritation.

Follicular Lumen: The hair follicle canal. The sebum secreted by sebaceous gland is discharged into the follicular lumen.

Foreign Body Reaction : The human body tissues, including skin, recognize new chemical or physical substances introduced into it as foreign or "non-self" and set up defense against these by launching an immune reaction against these. Sometimes, the body mistakenly recognize its own (altered) cells and tissues as foreign and launch attacks on them, causing unpredictable damages. In skin, such foreign body reactions either help in getting rid of the invaders or result in the formation of what are known as granulomas, as are typically seen in tuberculosis, leprosy, sarcoidosis etc.

Back to Top

Acne Glossary : G

Gene: A unit of inheritance that contains the instructions, or code, that a cell uses to make a specific product, usually a protein. Genes are made of a substance called DNA. They govern every body function and determine inherited traits passed from parent to child.

Genetic disease: Hereditary diseases transmitted through genes.

Genetics: The study of how diseases, conditions, and traits are inherited through the genes. e.g.: Cystic Fibrosis, neurofibromatosis, tuberous sclerosis, lamellar icthyosis etc.

Guided imagery: A way to reduce stress by focusing on suggested mental visualizations.

Back to Top

Acne Glossary : H

Hair Follicle: This is the hair unit, which consists of the hair root, hair matrix or shaft, hair lumen and the associated glands of sebaceous glands, and, at places, apocrine glands.

Herpes zoster (Syn.Shingles): A common viral infection of the nerves caused by varicella zoster virus, characterized by a painful skin rash or eruption of small blisters on an erythematous base anywhere on the body along the distribution of a cutaneous nerve.

Histological examination: The study of a tissue specimen by staining it and examining it under a microscope.

Heredity: The transmission of traits from one generation to the next.

Holistic medicine: Natural healing directed at an individual�s physical, spiritual, and emotional needs.

Home phototherapy: The therapeutic use of an ultraviolet light source in the home, as prescribed by a doctor.

Hormone: A chemical substance that the body produces to regulate the activity of organ(s) or tissue(s).

Hyperkeratosis: Increased thickness of horny layer with or without increase in the thickness of the granular cell layer.

Hyperplasia (Syn.Hyper proliferation): An increase in number of cells in a tissue. Hyperplasia may be irregular, psoriasiform, or pseudo epitheliomatous.

Hypertrophic Scar: A hypertrophic scar is caused by excessive collagen deposition at the site of wound healing.

Back to Top

Acne Glossary : I

Immune deficiency: The body�s inability to maintain an intact immune system.

Immune response: The reactions of the immune system to foreign substances.

Immune system: An intricate network of specialized cells and organs that work together to defend the body against attacks by foreign substances such as bacteria and viruses.

Immunologic: Pertaining to the immune system.

Immunocompromised: An abnormal condition in which one's ability to fight infection is decreased. This can be due to a disease process, certain medications, or a condition present at birth.

Impetigo: A bacterial skin infection characterized by pus-filled blisters.

Immunity: The condition of being immune, the protection against infectious disease conferred either by the immune response generated by immunization or previous infection or by other non-immunologic factors.

Incidence of disease: Rate, range or amount of occurrence or influence of a disease. Also denote number of new years per annum, compared to prevalence, which is the total number of cases that are present at any given time. See alsoprevalence of disease.

Inflammation: A characteristic reaction of tissues to injury or disease. It is marked by four signs: swelling, redness, heat, and pain.

Back to Top

Acne Glossary : J

Acne Glossary : K

Keloid: A hypertrophic scar, which continue to grow un-checked by deposition of excessive connective tissue collagen.

Keratinization: The process through which the epidermal cells mature by deposition of the keratin. Keratin: A family of proteins that form the primary chemical components of the skin, hair, and nails.

Keratolytic: An agent that promotes the softening and peeling of the epidermis. e.g. Salicylic acid.

Keratinocytes: The cells in the epidermis that manufacture the fibrous protein keratin. The primary cell types found in the epidermis, the outer layer of skin.

Back to Top

Acne Glossary : L

Leucocytes: Generic term for a white blood cell. The family consists of polymorphonuclear neutrophils (polymorphs or neutrophils), lymphocytes, eosinophils, basophils and monocytes. T

Lichenification : Thickening and pigmentation of skin caused by chronic friction or scratching.

Lesion: An abnormal change, usually well defined, in the structure of an organ or part of the body; caused by injury or disease. e.g. a patch of skin affected by acne.

Lymphocyte: White blood cells that fight infection and disease. Two types of lymphocytes are derived from bone marrow. Lymphocytes of one type migrate to thymus where they differentiate and then are dispersed to peripheral lymphoid tissue as thymus derived or T lymphocytes. They account for 80% of the circulating lymphocytes. The other type of lymphocytes mature in bone marrow and are designated as B lymphocytes. They account for 20% of the circulating lymphocytes.

Back to Top

Acne Glossary : M

Macule: Macule is a flat, circumscribed skin discoloration of less than 0.5 cm that is neither elevated or depressed. e.g. Vitiligo, Cafe au lait, Freckles. When the size is more than 0.5 cm, called a patch.

Macrophage: A large phagocytic cell of the mononuclear series found within tissues. Also called an "antigen-presenting cells," macrophages destroy foreign antigens and initiate T cell activation.

Maintenance program: A treatment program that is initiated to keep a disease in remission after an intensive course of therapy.

Malignant melanoma: A potentially fatal form of skin cancer.

Mast cell: Cells probably derived from basophils present in tissues. Participates in 'Immediate hypersensitivity' reactions by release of various chemical mediators like histamine responsible for allergic reactions like urticaria or hives.

Melanocytes: Cells present in the epidermis that produce melanin (skin pigment).

Microcomedone : The formation of the small keratinous plug at the hair follicle pore to block the release of the sebum to the surface. This is the primary pathology in acne.

Milieu interior : The internal environment within the cell and the surrounding tissue. When the stability of the milieu interior is disturbed, the result is dis"ease".

Back to Top

Acne Glossary : N

Narrow-band UVB: Ultraviolet light in a narrow band of 311 nm to 313 nm, which is faster acting, and possibly safer and effective than other photo therapies.

Neutrophils: See polymorphonuclear leukocyte

Nodule : A deep seated bump, sometimes can be felt and seen above the skin surface.

Nodulo-cystic acne: A very severe scarring type of acne with deep seated nodules and cysts filled with sebum and pus.

Back to Top

Acne Glossary : O

Open Comedone: See blackhead.

Over-the-counter (OTC): Medication that can be purchased without the doctor's prescription.

Back to Top

Acne Glossary : P

Papule: Elevated, solid lesions less than 0.5 cm in size. e.g.: Skin tags, lichen planus, papular acne.

Patch: Flat, circumscribed skin discoloration, more than 0.5 cm in diameter. A large macule.

Photosensitivity: Photosensitivity refers to a skin reaction in response to the sun; it tends to occur when something, such as an infection or a medication, increases a person's sensitivity to ultraviolet radiation.

Phototherapy: The use of natural or artificial UV light to treat disease.

Pilo-sebaceous unit : This is the unit which consists of the hair follicle and the associated sebaceous glands, the main players in causing acne.

Plaque: Elevated, solid and confluence of papules (more than 0.5 cm in diameter) that lacks a deeper component. e.g. Psoriasis, Bowenoid disease, Mycosis fungoides, Tinea corporis, Eczema.

Polymorphonuclear leukocyte: White cell, granular cytoplasm. Neutral staining (neutrophil) - most frequent, phagocytic. Basophilic staining - basophil. Eosinophilic staining - eosinophil.

Prevalence of disease: Prevalence means the total number of a disease in a community or country at any given period of time. See also incidence of disease.

Prognosis: Prognosis is the term used to define the normal course and outcome of a disease and chances of cure by following a particular line of therapy.

Propionibacterium Acnes: A diphtheroid bacteria, normal resident of hair follicle. Feeds on sebum. The action of these bacteria is responsible for the production of irritating bye products of sebum and some of the changes in acne.

Pus: Thick, opaque, usually yellowish-white fluid made up of dead tissue, dead bacteria, and white blood cells, usually a sign of presence of infection.

Pustule: A small, circumscribed elevation of the skin containing pus.

Back to Top

Acne Glossary : Q

Acne Glossary : R

Receptor: Structures on the surface of cells that serve as attachment sites for other cells or signaling molecules to relay information or trigger a reaction.

Remission: The period during which the symptoms of a disease decrease or subside.

Retinoids: Vitamin A derivatives often used in topical or oral psoriasis and acne therapy.

Rotational therapy: A strategy in which a doctor rotates a patient�s treatments periodically, from one to another, to reduce toxicity and to allow for longer periods of benefit from each agent.

Back to Top

Acne Glossary : S

Scabies: A skin infestation of scabies mites characterized by severe itching and excoriations.

Scales: Dead skin cells that look like flakes or dry skin. In psoriasis, these are characteristically silvery white in color.

Scar: Fibrous tissue that is formed after a skin injury.

Salicylic acid: A keratolytic drug (a drug that removes the outer layer of skin) that is used to treat various skin conditions.

Scalp acne: Folliculitis (inflammation of the hair follicle) that appears on the scalp. It is often itchy and painful.

Sebaceous glands: Glands in the skin that secrete oil (sebum) to the surface of the skin. Acne and seborrhoeic dermatitis are two conditions affecting the sebaceous glands.

Sebum: Sebum is the oily liquid produced by the sebaceous glands associated with the hair follicle. Normal function of sebum is to keep the moisture of the skin and make skin soft and supple.

Skin biopsy: Taking a small piece of skin to be examined under a microscope. This procedure is usually performed with the aid of a local anesthetic, and helps a dermatologist diagnose the type of skin disorder.

Skin thinning: A condition in which the skin atrophies due to any variety of causes, including overuse of topical steroids.

Steroids (Cortico-steroids): A synthetic hormone similar to that produced naturally by the adrenal glands that is available in pill, topical cream, and injectable forms.

Stress (Syn.Tension): Stress occurs when the demands upon an individual cannot be met with the resources available. Stress has far reaching effects on the body and mind. Stress is known to be a trigger for acne.

Stressors: Any of a number of factors that can cause an individual to experience physical or emotional stress.

Support group: A gathering of people who share a common concern or have a common interest. The support groups meet regularly to exchange ideas, discuss problems and offer emotional support to each other.

Systemic: Affecting the entire body.

Systemic treatment: A treatment, such as a pill or an injection that will affect the whole body.

Squamous cells: The primary cell types found in the epidermis, the outer layer of skin, also called keratinocytes.

Seborrhoeic dermatitis (Syn. Severe Dandruff): An inflammatory condition of the skin characterized by increased sebum secretion and yeast infection, scaling, flaking and itching. Commonly seen on the scalp face, front and back of chest.

Signs: What the doctor finds and describes as the clinical presentation of a disease.

Symptoms: What the patient complains of.

Stratum corneum: Upper most horny layer of the epidermis. Consists of dead cells.

Sub cutis: The deepest layer of skin; also known as the subcutaneous layer.

Back to Top

Acne Glossary : T

Tazarotene: Vitamin A topical medication for the treatment of psoriasis and acne.

Telangiectasia: Dilatation of blood vessels mostly of venules but also of capillaries and arterioles. This can become evident beneath the thinned epidermis due to prolonged application of topical corticosteroids.

T cells (Syn.T lymphocytes): Cells that either initiate the immune response (helper T cells) or actively target and destroy cells perceived as foreign (killer T cells). The T lymphocytes play an important role in normal cutaneous immune surveillance and in delayed hypersensitivity reaction. T lymphocytes are activated through the presentation of antigens by Antigen presenting cells (APC) or macrophages. They then release chemical messengers known as cytokines, which are responsible for a wide range of cellular and vascular inflammatory responses seen in diseases like psoriasis.

T-cell receptors: molecules on the surface of T cells that are the sites for macrophages to "present" antigens to the T cell and trigger an immune response.

Tretinoin: A drug which is chemically related to vitamin A; used to treat acne and scaly skin disorders like psoriasis.

Topical agent: A treatment such as a cream, salve, or ointment that is applied to the surface of the skin.

Toxicity: The potential of a drug or treatment to cause harmful side effects.

Back to Top

Acne Glossary : U

Urticaria (Syn.Hives): A condition in which red, itchy, and swollen areas appear on the skin- usually as an allergic reaction from food, medications, contact allergy, infections etc. Most often, a cause could not be identified.

Ultraviolet (UV) light: The type of light that emanates directly from the sun. It is classified into three categories according to wavelength: UVC, UVB, and UVA. Ultraviolet light can also be simulated from artificial light sources. This is an effective treatment for psoriasis and vitiligo.

UVB phototherapy: Treatment involving measured doses of UV light in the UVB wavelength. Two types are broadband UVB, and the less common narrow-band UVB.

Acne Glossary : V

Vesicle: A clear fluid filled sac, a blister less than 0.5 cm in diameter.

Vitamin A: Derivatives of this vitamin, called retinoids, are used in its oral and topical forms to treat acne.

Vitiligo: Smooth, white patches in the skin caused by the loss of pigment-producing cells, thought to be an autoimmune disease of melanocytes.

Back to Top

Acne Glossary : W

Wart(Syn. Verruca): A benign skin growth caused by a virus known as Human Papilloma Virus.

White Blood Cell: Cells that help the body fight infection and disease.

Whitehead: See closed comedone.

Wheal (Syn. Hive): Firm, edematous plaque that is evanescent and itchy.

Back to Top

Acne Glossary : X

Acne Glossary : Y

Yoga: An ancient system of holistic healing involving relaxing breathing and postural exercises.

Back to Top

Acne Glossary : Z

Back from Acne Glossary to Home Page