In dark skin, cold sores look like small blisters filled with clear liquid. This liquid eventually leaks and causes the sores to crust over. After a while, this crust falls off on its own.

People with light skin might notice more redness around their cold sores, but otherwise, their appearance is roughly the same across skin tones.

People with dark skin may be more likely to experience post-inflammatory hyperpigmentation after their cold sores heal, though most heal without leaving any lasting mark.

Read on to learn more about cold sores in dark skin, including what they are, what they look like, and their treatment options.

A woman with darker skin looking at a compact mirror to check for cold sores. She wears a black head covering and is standing under a willow tree.Share on Pinterest
Amaal Said/Getty Images

Cold sores are small, fluid-filled blisters that tend to affect the sides of the mouth. They tend to develop due to the herpes simplex virus type 1 (HSV-1). Less commonly, they can be the result of the herpes simplex virus type 2, which causes genital herpes.

HSV-1 mainly spreads through mouth-to-mouth contact with someone who has the virus. Once a person has the virus, it stays in their body throughout their life. Around 67% of people under 50 years of age have HSV-1, but, in most cases, the virus causes no symptoms.

Some people experience cold sores if the virus moves into the nerve cells near the lips. These sores may reappear if the virus reactivates, which can happen periodically for a variety of reasons.

Cold sores look similar across all skin types. However, in dark skin, they may not be as red as they are in light skin.

At the blister stage, cold sores have a white or clear appearance because they contain fluid. When cold sores break open, fluid seeps out, and they crust or scab over as they heal.

Cold sores can appear in places other than the mouth. They are contagious, so if a person scratches or touches the sore without washing their hands, they may spread the virus that causes them to other areas of the body.

Rarely, people with eczema and other chronic skin conditions may notice that cold sores affect larger areas of skin. If this happens, they should seek medical treatment as soon as possible. If someone notices a cold sore developing near the eye, they must seek medical attention immediately.

The symptoms of HSV-1 and the cold sores it causes can vary depending on whether a person has a new HSV-1 infection or an older infection has reactivated.

New viral infection

Most people develop new HSV-1 infections as children. These infections may not cause any symptoms, but if they do, a person may experience numerous painful sores on the tongue, gums, lips, or throat. These sores may be accompanied by a burning sensation.

Some other possible symptoms include:

These symptoms may last for 1–2 weeks. After the initial infection, the body usually starts to produce antibodies that keep the virus under control.

Reactivation of an old infection

When HSV-1 reactivates, the symptoms are usually milder than they were during the initial infection. The sores typically appear on one side of the mouth, going through several stages as they appear, burst, and heal:

  1. Warning signs: During this stage, a person may feel burning, itching, stinging, or numbness where the cold sore is about to appear. Usually, this happens 1–2 days before the development of the sore.
  2. Cold sore appears: Next, the cold sore appears on the lips or near the mouth. Sometimes, sores may appear elsewhere. Avoid touching cold sores at this stage, and do not pick or pop them.
  3. Crusting: Within 48 hours, the sores burst and leak the fluid inside. This then forms a crust as they heal.
  4. Healing: In most people, it takes 5–15 days for a cold sore to heal completely. If it takes longer than this, or if someone has an underlying condition that affects their immune system, they may need treatment.

There is currently no cure for the virus that causes cold sores, but treatment can reduce the symptoms and speed up the time it takes for them to heal.

Sometimes, receiving early treatment can also prevent cold sores from developing after the initial warning signs.

Some treatment options include:

  • topical antiviral creams or patches that contain acyclovir or penciclovir
  • topical pain medications, such as lidocaine
  • antiviral medications, such as acyclovir, famciclovir, and valacyclovir

For the best results, people should aim to use antiviral treatments as soon as the early symptoms appear. People can also adopt behaviors that reduce irritation until the cold sores heal, such as:

  • applying a cold compress to the area for 5–10 minutes a few times per day
  • temporarily avoiding acidic, salty, and spicy foods
  • wearing a lip balm that contains SPF 30 or above
  • gently applying petroleum jelly to protect dry or chapped skin

People should remember to wash their hands with soap and water after touching a cold sore. Also, they should use clean towels and washcloths to apply ice, and they should launder them after use.

Although cold sores do not usually leave any lasting marks, they may cause hyperpigmentation or scarring in some cases — particularly if a person scratches, picks, or pops the sores.

Hyperpigmentation is more likely to occur in dark skin because it has more melanocytes, which are the cells that produce melanin. When the top layer of skin becomes injured, the skin can produce more melanin in response to the damage. This causes the skin to darken.

Hyperpigmentation may fade over time, but in people with dark skin tones, it can be more intense and last longer. If hyperpigmentation does occur, it is important to speak with a dermatologist before trying any treatments to fade the discoloration.

Some of the standard treatments for hyperpigmentation can further irritate the skin and may lead to more cold sores developing. Some, such as tretinoin, can also make the skin more sensitive to UV light, which is another potential cold sore trigger.

It is not always possible to prevent new cold sores, but there are some factors that can trigger a reactivation of the virus that causes them.

These triggers include:

  • exposure to UV light
  • stress
  • tiredness
  • a viral illness, such as a cold
  • a cut or injury near the mouth
  • certain cosmetic procedures, such as laser treatments
  • hormonal changes during the menstrual cycle

Wearing a lip balm with SPF daily can protect the skin from UV light. If possible, people should also take steps to reduce stress and avoid getting other viral infections.

Several other skin conditions can resemble cold sores.

These conditions include:

It is important to speak with a doctor to confirm a diagnosis of HSV-1 and rule out other possibilities. A person should also consult a doctor if they have cold sores that are severe, that are very painful, or that spread to other parts of the body.

Cold sores on dark skin look like small, fluid-filled blisters. They may ooze or form a crust that sits on top of the skin until it falls off.

In dark skin, cold sores may appear less red than they do in light skin.

Usually, cold sores heal on their own without any scarring or complications. Over-the-counter cold sore creams or patches can speed up healing. Alternatively, a doctor can provide prescription medications for persistent or severe sores.