Glossary of Common Rosacea Medical Terms

  • Blepharitis: Inflammation of the eyelids.

  • Cathelicidins: A type of antimicrobial molecule that is part of the innate immune system’s response to infection, and plays a role in the inflammation associated with rosacea.

  • Chalazion: A cyst on the eyelid due to plugging of the meibomian glands, fat-secreting glands of the eyes.

  • Comedone: A plugged hair follicle. May be open (blackhead) or nearly closed (whitehead).

  • Comorbidity: The occurrence of two disorders or illnesses in the same person, at the same time or one after another. Comorbidity does not necessarily mean that one causes the other.

  • Controlled study: An experiment or clinical trial that includes an untested comparison group, referred to as a "control group."

  • Cutaneous: Pertaining to the skin.

  • Demodex mites: Microscopic mites that are a normal inhabitant of human facial skin and eyelashes, but are often found in greater numbers on the skin of rosacea patients. Whether the higher incidence is a cause or result of the disease has not been determined.

  • Double-blind: A research procedure in which neither the patient nor the investigator knows who is receiving the experimental substance or procedure and who is receiving a placebo. Done to avoid bias in the study.

  • Edema: Swelling from abnormally large amounts of fluids in the tissues.

  • Erythema: Abnormal redness of the skin.

  • Erythematotelangiectatic rosacea: Formerly referred to as “subtype 1,” a common presentation of rosacea characterized by flushing and persistent redness. Visible blood vessels may also appear.

  • Flushing: Transient redness of the face and neck.

  • Granuloma: A tumor-like mass or nodule of tissue.

  • Granulomatous rosacea: Variant of rosacea, characterized by hard yellow, brown or red papules or nodules.

  • Innate immune system: The body’s first line of defense against infection, composed of a complex of immune cells that trigger one or more defense responses when they encounter bacteria, viruses or other pathogens.

  • Mast cells: A type of white blood cell located at the intersection of the nervous system and vascular system that is involved in the pathophysiology of rosacea.

  • Nasolabial folds: The creases or “laugh lines” that run from the nose to the corner of the mouth.

  • Neurovascular: Relating to or involving both the nerves and the blood vessels.

  • Nodule: A small node that is solid and can be detected by touch.

  • Ocular rosacea: Rosacea affecting the eyes, characterized by watery or bloodshot appearance, irritation, and/or burning or stinging. Formerly also referred to as “subtype 4.”

  • Papule: A small, dome-shaped, solid, usually inflamed elevation of the skin.

  • Papulopustular rosacea: Formerly also referred to as “subtype 2” rosacea, characterized by facial redness with bumps or pimples.

  • Paranasal: Alongside the nose.

  • Pathophysiology: The process or mechanisms by which a disease develops or progresses.

  • Phenotype: An observable characteristic that may result from a genetic or environmental influence, i.e., signs and symptoms of rosacea.

  • Phymatous rosacea: Formerly also referred to as “subtype 3” rosacea, characterized by thickening or growth of excess tissue, often around the nose.

  • Placebo: An oral or topical formulation without this active ingredient, used for comparison with the active medication in controlled clinical studies.

  • Plaque: Elevated red patch on the skin.

  • Pustule: A small elevation of the skin filled with a white substance.

  • Recalcitrant: Not responsive to treatment.

  • Rhinophyma: Enlargement of the nose with excess tissue, a common form of phymatous rosacea.

  • Subtype: A common pattern or grouping of signs and symptoms, are now considered outmoded. The classification of rosacea now focuses on individual signs and symptoms, or phenotypes.

  • Subtype 1 rosacea: Erythematotelangiectatic rosacea, characterized by flushing and persistent redness. Visible blood vessels may also appear.

  • Subtype 2 rosacea: Papulopustular rosacea, characterized by facial redness with bumps or pimples.

  • Subtype 3 rosacea: Phymatous rosacea, characterized by thickening or growth of excess tissue, often around the nose.

  • Subtype 4 rosacea: Ocular rosacea, characterized by watery or bloodshot appearance, irritation, burning or stinging of the eyes.

  • Telangiectasia: Small blood vessels visible through the skin.