Glossary of Medical Terminology

Curious about a skin condition you may have? Check out our Medical Terminology Glossary below to help determine what it may be. Please note – this is not intended to be a complete glossary. It is simply a brief introduction for informational purposes only.

Be sure to contact us to set up an appointment with our board-certified dermatologist Dr. Thomas Balshi. He can assess your concerns, perform a complete examination, and provide expert treatment.


Another word for pimples, or bumps that you get mostly on your face. Most acne happens when your skin makes too much oil. The oil mixes with dead skin cells and germs called bacteria to plug up the little holes in your skin called pores.


Your body overreacts to something that doesn't cause a problem for most people. Sneezing, itching or developing a rash are some ways your body can overreact.

Aloe Vera

A plant that is used to make a gel that treats burns, including sunburns.


A disease that can cause your hair to fall out.

Angel Kiss

A type of birthmark that is pink or red and usually shows up on your face at birth. It's also called a salmon patch.

Atopic Dermatitis

The most common kind of eczema, a disease that causes itchy, red, irritated skin.

Barrier Repair Moisturizer

A cream that protects your skin and keeps it moist. It can help treat eczema.


A medicine used in ointments to stop pain on the skin.

Benzoyl Peroxide

Medicine used to treat pimples. It kills the bacteria and gets rid of some of the oil and dead skin cells.


Little bits of dry skin that form on your scalp and flake off.


A word for eczema, or itchy, red, irritated skin.


The second layer of your skin, which you can't see. It's the layer from which your hair starts growing and it's where sweat is made.


A disease that makes skin irritated and itchy. Eczema often causes a rash that is red, blistering, oozing, scaly, or brownish. There are lots of kinds of eczema, but the most common is atopic dermatitis.


The top layer of your skin.


Tiny pockets in your skin from which hair grows.


Tiny pockets in the body. In the skin, glands store oil that keeps skin and hair moist.


A type of birthmark. Some are bright red and look like strawberries and some are bluish-purple and make the skin swell and bulge.


Bumps that can pop up on your skin when you've been exposed to something that you are allergic to, or that bothers your body. They can itch or sting.

Ingrown Toenail

This can happen when the side of your toenail grows into your skin, and it can hurt a lot. The best way to prevent it is to cut your toenails straight across.


A thick bumpy scar that can happen after a piercing or after stitches.


Tiny bugs that like to live in your hair. Lots of children get them. They spread when kids put their heads together or share things like hats, combs and brushes.


A medicine used in creams and ointments to stop pain.

Light Therapy

A treatment with lights used by dermatologists to help skin diseases such as eczema.


The little white half-moon shape on your nail nearest your skin. You might only be able to see it on your thumbnails, or not at all.

Lyme Disease

A type of disease that you can get if you get bitten by a certain type of tick. It may cause a red, donut-shaped (or bull's-eye) rash. A tick is a tiny, round bug that can attach itself to you when you're walking through the woods. Wear long pants and bug spray to keep them away from your skin.


A little pocket in your skin where your nail grows from.


The stuff in your body that gives your skin and hair its color. The more melanin you have, the darker your hair or skin. Also called pigment.


Cells in your body that process melanin, which is what gives skin and hair its color.


Melanoma is a form of skin cancer that arises when pigment-producing cells—known as melanocytes—mutate and become cancerous.


A lotion, cream or gel that can help keep your skin soft and smooth.


Small spots on your skin that can be brown, pink, black or other colors. They are usually normal and may be there when you're born, or can show up later in life.

Molluscum contagiosum

Molluscum contagiosum is a relatively common viral infection of the skin that results in round, firm, painless bumps ranging in size from a pinhead to a pencil eraser.

Oil Glands

Little pockets in the skin where oil is made. The oil keeps your skin and hair from drying out.


A hard pimple. A papule is a firm type of pimple that happens when blocked pores get so irritated their walls break.


The material in your body that gives your skin and hair its color. The more pigment you have, the darker your hair or skin. Also called melanin.


Bumps that you get on your face and sometimes your neck, back, and chest that appear when excess oil and dead skin cells get trapped in the pores of the skin.

Plantar Wart

Small growths that usually appear on the heels or other weight-bearing areas of your feet.

Poison Ivy

A type of plant found in the woods that can give you a very itchy rash called contact dermatitis.

Poison Oak

Like poison ivy, poison oak is a type of plant found in the woods that can give you a very itchy rash called contact dermatitis.

Poison Sumac

Like poison ivy and poison oak, poison sumac is a type of plant found in the woods that leads to an itchy, burning allergic skin reaction. Poison sumac is considered more allergenic than both poison ivy and poison oak.

Salicylic acid

A type of pimple medicine that helps unplug blocked pores.

Salmon patch

A type of birthmark that is pink or red and usually shows up on your face, neck or back at birth.

Skin Cancer

A disease that can happen when some cells in the skin get damaged and start growing too fast. The sun is a major cause of skin cancer.


A number that tells you how your sunscreen will protect you from the sun's UVB rays. The higher the number, the greater the sun protection. Choose a broad-spectrum sunscreen with an SPF of at least 30 and reapply it about every two hours.


Very clean, without any germs on it.

Stork Bite

A type of birthmark that is pink or red and usually shows up on your neck at birth. It's also called a salmon patch.

Subcutaneous fat

The bottom layer of the skin. It attaches the rest of your skin to your muscle and bones, and controls your body temperature.

Sweat Glands

Little pockets in the second layer of your skin - the dermis - where sweat is made. Sweat helps keep you cool when you're active.

Ultraviolet rays/UV rays

Light rays that the sun gives off. Tanning beds also can give off UV rays. The rays can damage the skin and cause skin cancer and wrinkling.


The oil in poison ivy, poison oak, and poison sumac that can cause an allergic reaction. When it touches the skin, most people get an itchy rash.


UVA light, also known as long-wave light, accounts for about 95% of the UV light that reaches our skin. Although both UVA and UVB are bad for skin, UVA rays are more of a threat because a much larger percentage of them reach earth's surface. They’re present all day long, year-round, even when it’s cloudy and the sun “isn’t out.”


Although not as skin-penetrating or ever-present as UVA rays, UVB light is powerful: It’s directly responsible for sunburn and other visible changes to skin’s surface, including discolorations. UVB radiation also plays a role in skin cancers.


A poisonous liquid that some bugs inject when they bite or sting you. It can make you itch or even make you sick.


A type of germ that can cause an infection, such as a wart.


A small, fleshy bump on the skin that are caused by a virus.

West Nile Virus

A type of disease that you can get when you're bitten by certain mosquitoes. It's a good idea to use bug spray to keep them away.


A type of pimple that looks white because the clogged pore is closed and looks whitish on top.