- Blepharitis: Inflammation of the eyelids.
- 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.
- 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: Subtype 1 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.
- Nasolabial folds: The “laugh lines” that run from the nose to the corner of the mouth.
- Nodule: A small node that is solid and can be detected by touch.
- Ocular rosacea: Subtype 4 rosacea, characterized by watery or bloodshot appearance, irritation, burning or stinging of the eyes.
- Papule: A small, dome-shaped, solid, usually inflamed elevation of the skin.
- Papulopustular rosacea: Subtype 2 rosacea, characterized by facial redness with bumps or pimples.
- Paranasal: Alongside the nose.
- Phymatous rosacea: 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.
- 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: Blood vessels visible through the skin.