Cold sores are painful skin lesions that occur on the face due to the herpes simplex virus (HSV-1). They all follow a 5-stage life cycle. The healing process is similar to other ‘injured’ areas of skin. Scabbed areas (during stage 4) can sometimes change color to black.

While it may be alarming to see a black scab on your lip or the corner of the mouth, it’s unlikely to be a reason for medical concern. It is common for blood to emerge from the skin during the ulceration stage (stage 3). Blood under the forming scab is the reason for the areas of discoloration.

We aim to help you understand the scabbing process. You will find out how to identify an infection and look after a cold sore scab so that it can heal quickly and safely. We’ll start by looking at the primary reasons for why a cold sore scab has turned black.

What Causes a Cold Sore Scab to Turn Black?

A black cold sore scab is primarily the result of dried blood being trapped under the skin. This occurs when the blood has been deoxygenated. Once blood leaves the body, it darkens due to a lack of oxygen. Blood on the surface of the lip, yet trapped underneath, is often black.

To further understand the process, we need to revisit the cold sore stages briefly. Prior to the scab stage is the ulceration stage where it is common for bleeding to occur. If any blood is present (dried) while it is forming, then a black scab is likely to occur.

They have a variety of colors once they’re exposed to air. They can even change colors before they flake away, but this process is normal.

To summarize…

  • Black scabs during cold sores are caused by dried deoxygenated blood being trapped underneath. Without oxygen, any blood that’s outside of the body will turn black. They can take on a multitude of colors, but they’ll be gone within a few days.

Is a Black Scab a Sign of Infection?

They are not a sign of infection if the visual is the only issue. You should only be concerned about the color if it is met with redness, swelling, bleeding or the drainage of fluid. The color is not a sign of a cold sore infection.

Most infected sores fail to reach the scabbing stage because there’s too much disruption. A scab is a sign of natural healing, so it is quite rare for an infected sore to form a scab. If you are fearful of an infection, your best course of action is to monitor the situation.

To recap…

  • The appearance of a black scab is not a sign of infection.
  • You should not be alarmed unless it begins to turn red, swell, bleed or drain a pus-like fluid.
  • The likelihood of developing an infection during this stage is low. Fever blisters that are infected before the scab stage rarely form a scab. It is the last stage before the reveal of new skin. Blisters that have been infected are too disrupted to form a scab.

Is Treatment Required for a Black Scab?

There is no special treatment required unless you are displaying symptoms of infection. If you have been treating your cold sore with an OTC medicine, you should continue to do so during this stage. No changes have to be made due to the color.

While it is not visually appealing, you should avoid removing it prematurely. This will lead to red marks or scarring.

To summarize…

  • Unless it’s showing signs of infection, no special treatment is required.
  • While a black scab isn’t appealing, turning to a quick fix is not safe. Don’t remove it.

Should I Keep the Scab Moist or Dry?

Although there are many schools of thought, and pros and cons to both, keeping a scab dry or moist is your decision.

A moist scab is less irritated if it is moistened by an OTC cream, such as Abreva. In this environment, it is more likely to stay together and be less of an issue. The natural healing process, coupled with treatment, will heal the overall sore within a few days.

A dry scab, while quite flaky, itchy, and potentially painful, is more likely to fall apart without moisture. Although keeping your scab moist is the safest way to proceed, a dry scab may heal faster.

To recap…

  • It is best to keep it moist. However, allowing it to dry out is fine as long as you are careful.
  • Many alternative methods are based on the “drying out” technique. Removing the moisture from a sore will typically heal the site faster. Although safe healing should always be your goal, drying out a sore will likely garner faster results.
  • Removing a cold sore scab early will mean that the healing process will need to start again. You may also experience permanent scarring.

How Long Does a Cold Sore Scab Last?

Once formed, it typically lasts 72 hours and then falls off or flakes away. However, the scabbing process can last as little as 48 hours in some cases. It all depends on the treatment, the health of your skin, and what happens during the healing process.

With a treatment such as HERP-B-GONE, most cold sore outbreaks end in just days. Scabbing is much reduced. Your goal should be to heal healthily. How you handle the process will be a huge factor as to what your fever blister looks like by the end of the week.

To summarize…

  • The scab stage typically lasts 2-3 days on average. So much depends on the treatment option(s) that have been used.
  • Each stage of the cold sore cycle lasts for 24-72 hours. This is why patience is necessary.

What if the Scab Won’t Go Away?

At most, it should be gone within a week. Once it has flaked away, it will be replaced with skin that is a pink or reddish color. This skin overhauls the area that once had a cold sore.

Do not take aggressive (unwise) measures. Instead, continue to apply your OTC treatment. If nothing has changed after one week, you should consult your physician. Your issue could be connected to infection without the presence of any of the core symptoms.

So much of the scabbing process depends on the severity of the original outbreak. If you have a series of large blister clusters, more scabbing is inevitable. Although the process will be the same, a bigger scab might take a bit longer to heal.

To recap…

  • Continue to apply treatment if it isn’t healing. This could be a sign of an infection.
  • If your scab has remained after a full week, you may wish to consult your physician.
  • The healing often depends on how the virus was treated and the severity of the outbreak.

Why has my cold sore gone black?

How to Heal a Scab Faster

The process of drying out your cold sore will lead to faster results. Although the process may cause minor issues such as itching and general discomfort, the process does work.

When it comes to “faster healing” at any stage, you should never become too deliberate. Cold sores, with an OTC treatment, can be remedied in less than one week. However, removing a scab before it’s ready to fall off naturally can send you back to square one.

To summarize…

  • You can dry out cold sores with essential oils. Tea tree oil is a safe alternative if used in the right way.
  • Never be too eager to ‘cure’ your outbreak. If you choose the wrong path, it will only make the problem worse.

What if My Scab Falls Off Early?

If your scab falls off early, whether it’s via deliberate or accidental means, you should apply some aloe vera to the site. You must also address any bleeding and swelling that occurs. Apply a cold compress if the area begins to swell or become too painful. The use of oral anti-inflammatory medications is also an option.

The lack of a scab will set your healing time back and result in redness. The loss of a scab does not mean infection. If it was only hours away from falling off naturally, then its early departure will not be too harmful.

We encourage you to monitor your skin and continue to apply aloe vera. When it is removed in this way, it is possible for scarring to occur. While this is not common, it is something to be mindful of in the days after your outbreak has ended.

To recap…

  • If your cold sore scab falls off, you need to address the issue ASAP. Tend to any bleeding and swelling that occurs.
  • While the removal does not always mean infection, it is smart practice to monitor the area in the days after the outbreak has concluded. Removal of a scab very early in the recovery process can potentially leave a scar.

The most important takeaway is that a scab is normal even if it’s black. Any scab on the body can fall victim to infection. However, a scab formed by a healing cold sore is no different than one that has formed on your arm. Unless the area begins to swell and turn red there is nothing to fear.

Scabs can take on every color of the rainbow during the healing process. The stunning visual of a black scab is not an indicator of trouble. Don’t pick at it. Allow it to fall off in its own time when the body is completely healed.