Acanthosis nigricans (AN) is a skin condition that causes one or more areas of skin to darken and thicken. Often the skin with AN feels like velvet.
People who get this skin condition sometimes mistakenly believe that a dye or something else they touched has discoloured their skin. They try scrubbing away the discolouration. Vigorous scrubbing will not get rid of AN.
Acanthosis nigricans is not contagious. It is not harmful.
Sometimes, it is a warning sign of a health problem that requires medical attention. For this reason, it is important to see a dermatologist if you notice an area of darker, thicker skin.
Acne is a skin condition that can cause one or more of the following:
- Acne cysts or nodules (deep, painful breakouts)
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.
When acne breakouts penetrate the skin deeply, they damage the skin and the tissue beneath it. As the acne clears, the body tries to repair this damage.
During the healing process, the body produces collagen—a substance that gives the skin support. If the body produces too little or too much collagen, you will see a scar.
The type of scar depends on how much collagen your body makes.
Depressed acne scars: If the body produces too little collagen, depressions or pits form as the skin heals.
Raised acne scars: Sometimes the body produces too much collagen as it tries to heal the skin and underlying tissue. When this happens, a person develops a raised acne scar. This type of acne scar is more common in people who have skin of colour like African Americans, Hispanics, and Asians.
Even when we do our best to prevent acne scars, some people scar. There are many treatment options, which can significantly diminish depressed and raised acne scars.
An actinic keratosis often appears as a reddish spot (as shown here) that develops on skin you seldom protected from the sun over the years.
These precancerous skin growths are common because many people seldom protect their skin from the sun with sunscreen, clothing, and shade. Without sun protection, the sun’s harmful rays can damage your skin. While your body may repair some of this damage, the sun’s rays continue to damage unprotected skin. Over the years, this damage builds up and can cause precancerous changes to your skin.
This is a disease that develops when the body attacks its own hair follicles (where hair grows from), which can cause hair loss anywhere on the body.
Many people who develop alopecia areata develop a round or oval bald patch on their scalp. The hair loss tends to be unpredictable. Hair may regrow without treatment. This happens more often when someone has a few bald patches. When the hair regrows, it may fall out again—or it may not.
If alopecia areata affects the nails, you may see dents, ridges, or brittle nails. Some people develop red nails.
Athlete's foot is a common fungal infection that most people get from walking barefoot in moist public places, like a swimming pool deck or locker room.
Despite the name, athlete’s foot can happen to anyone. It can result in flaky skin, cracking, and itchiness on the soles of the foot and between the toes.
Often called eczema or atopic eczema, this is a condition that usually develops by 5 years of age and causes extremely itchy rashes that come and go.
Atopic dermatitis (AD) is common worldwide. People of all ages from newborns to adults 65 years of age and older live with this condition. Symptoms range from excessively dry, itchy skin to painful, itchy rashes that cause sleepless nights and interfere with everyday life.
BASAL CELL CARCINOMA
The most common type of skin cancer, basal cell carcinoma can show up on the skin in many ways.
Most people who develop this skin cancer have fair skin that they seldom protected with sunscreen or sun-protective clothing. Before they developed skin cancer, they often noticed signs of sun damage on their skin, such as age spots, patches of discoloured skin, and deep wrinkles.
Although BCC is most common in people who have fair skin, people of all colours get this skin cancer. For most people, BCC is not life-threatening. It tends to grow slowly. It seldom spreads to another part of the body. Even so, treatment is important. When found early, this skin cancer is highly treatable. An early BCC can often be removed during an appointment with your dermatologist.
Bed bugs are tiny insects that feed on human blood. They hide in dark places close to where humans sleep and usually crawl out to feed while people are fast asleep.
If you have bed bugs in your home, it's unlikely that you'll see one unless you look for them. Bed bugs hide in the crevices of mattresses, box springs, headboards, couches, and other places. They only come out to feed.
While a bed bug is feeding on you, you're unlikely to notice. Most people are asleep when they get bit. Also, before a bed bug draws your blood, it injects you with a substance that prevents you from feeling the bite. When you wake up, you may notice itchy welts.
An adult that is full of blood can be the size of an apple seed. Hungry bed bugs and younger ones are about the size of a poppy seed.
If your baby has a birthmark, you’ll likely see a spot, patch, or lump that looks different from the rest of your baby’s skin. You may see this when your baby is born. Some birthmarks appear shortly after birth.
Birthmarks come in many shapes and colours. You may see a flat or raised mark. It may the size of a pinhead or cover a large area of your child’s skin. Most birthmarks fall somewhere in between. A birthmark can be pink, red, tan, brown, or any other colour. Some look like a bruise. Others look like a stain on the skin.
Some birthmarks are common. It’s estimated that between 3% and 10% of babies are born with a type of birthmark called a hemangioma. Other birthmarks, such a port-wine stain, are less common.
BOILS AND STYES
Boils are pus-filled skin infections that occur around a hair follicle or oil gland. This causes a red, painful lump to form as pus collects under the skin. A boil that occurs on the eyelid is called a stye.
Most boils and styes heal on their own within one to three weeks. However, if the pain or swelling worsens after several days, another boil or stye appears, or you develop a fever or vision problems with the infection, see a board-certified dermatologist.
Dermatologists use botulinum toxin therapy to diminish signs of ageing and to treat a medical condition called hyperhidrosis (excessive sweating).
This is a rare autoimmune disease that can cause large blisters on the skin. Blisters can develop on other areas like inside the mouth, but this is rare.
Bullous pemphigoid is a chronic disease, which means it lasts longer than six weeks. For many people, this disease lasts for months or years. As older blisters open and crust over, new blisters can appear.
Cellulitis is a common and potentially serious infection caused by bacteria. The bacteria infect the deep layers of skin and tissue beneath the skin.
The first sign of cellulitis is usually red and swollen skin. When you touch the infected area, it often feels warm and tender.
This infection can show up anywhere on the skin. Adults often get it in a lower leg. In children, cellulitis tends to appear on the face or neck.
A chemical peel can diminish many signs of ageing on the face as well as the hands, neck, and chest.
Chemical peels also treat some skin conditions. Dermatologists use chemical peels to treat some types of acne and conditions that discolour the skin.
Chickenpox is a highly contagious disease caused by a virus. Although the incidence of chickenpox has declined significantly since the development of the chickenpox vaccine, there are still children who develop chickenpox every year. Fortunately, there is a lot parents can do at home to help ease their children’s symptoms and prevent skin infections.
The most common symptom of chickenpox is a rash that turns into itchy, fluid-filled blisters and then scabs. The rash usually shows up on the face, chest and back first and then spreads to the rest of the body.
Other signs and symptoms of chickenpox may include:
- Loss of appetite
A cold sore is a small blister or group of blisters that usually develop on the lip or around the mouth. Cold sores are caused by the herpes simplex virus (HSV).
Cold sores are also known as fever blisters or herpes simplex labialis. The virus stays in the body after the cold sores clear. If the virus reactivates, or wakes up, you may get cold sores again.
Cold sores are generally not serious. In healthy people, cold sores tend to clear within two weeks. If you have a cold sore, you can spread the virus to others who don’t have the virus. Even when you treat cold sores, you can still spread the virus to others. You are contagious until all the sores have scabbed over.
When something that touches your skin either irritates it or causes an allergic skin reaction, you develop this skin disease. The first sign is often itchy skin, followed by a rash. You may also see blisters.
Contact dermatitis is not contagious, so you cannot give it to anyone else.
Because so many things can irritate our skin or cause an allergic skin reaction, contact dermatitis sends many people to see a dermatologist. While this may sound simple, finding the cause can be a challenge. More than 15,000 things that touch our skin can cause an allergic reaction. Some of the more common ones are fragrance and nickel, which are found in hundreds of products and everyday items. You can get a rash even if you only briefly touch something that causes an allergic reaction. This rash tends to appear hours or days after your skin touches what you’re allergic to.
CUTANEOUS T-CELL LYMPHOMA
Cutaneous T-cell lymphoma (CTCL) is a rare type of blood cancer.
It begins in a type of white blood cell called the T-lymphocyte (T-cell). T-cells help prevent infections and other diseases.
As odd as it sounds, most T-cells are found in our skin. That’s because our skin is the first line of defence against disease. The surface of an adult’s skin contains about 20 billion T-cells. That’s nearly twice as many T-cells as found in other parts of the body.
There are many types of CTCL. More than half the people who develop CTCL will have one of the following types:
- Mycosis fungoides
- Sézary syndrome