MOHS Surgery

Mohs Surgery Side Effects: Everything You Need to Know

Mohs surgery is the most successful skin cancer treatment. According to the American College of Mohs Surgery, it has a 99% cure rate for basal cell cancers and a 95% cure rate for squamous cell and recurrent cancers. It is also generally considered safe as most people recover smoothly without serious complications. But all surgeries have some degree of risk. Hence, in this article, we will talk about Mohs surgery’s side effects to learn more about it.

Despite the high success rate and low risk of complications, you might experience complications and side effects after undergoing Mohs surgery. This article highlights the side effects and complications of Mohs surgery.

What Is Mohs Surgery?

Mohs surgery, also called Mohs micrographic surgery, is a technique of removing skin cancers that involves cutting away the tumor in layers. During the surgery, the Mohs surgeon removes the visible portion of the tumor and a thin layer of surrounding healthy tissue. They divide the excised tissue into sections and examine each under a microscope to check for cancer cells. If any section has cancer cells, the surgeon removes another layer from the affected area and examines it for cancer cells. 

This process continues until the surgeon removes all the tissues with cancer cells. When the surgeon can’t find cancer cells in the excised tissue, they repair the surgical wound. This procedure minimizes the removal of healthy skin and maximizes the preservation of healthy tissue.

Mohs surgery is the most effective treatment for the two most common types of skin cancer: basal cell carcinomas and squamous cell carcinomas. It has also been used successfully in some cases of melanoma.

what is mohs

What Are the Benefits of Mohs Surgery?

Mohs surgery offers many benefits as a skin cancer treatment option. They include the following:

High Cure Rates

Mohs surgery has a 99% cure rate for basal cell cancers and a 95% cure rate for squamous cell and recurrent cancers. So, patients have a high likelihood of eliminating the cancer cells successfully. Patients are also less likely to need further inventions.

Maximal Tumor Removal and Tissue Preservation

The Mohs surgeon cuts away layer by layer and examines each in real time. This allows them to accurately determine the extent of the tumor and remove all of it until the remaining tissue has no cancerous cells.

Targeting also ensures they don’t remove any healthy tissues, which is particularly important for tumors in cosmetically sensitive areas like the face.

Minimal Scar Formation

Mohs surgery removes only tissues with cancerous cells, so it minimizes the size of the scar by preserving as much healthy tissue as possible.

Immediate Reconstruction

The surgeon can perform a skin graft on the same day if the patient wants. Immediate reconstruction reduces would closure time and results in better cosmetic results.

Suitable for Complex Cases

Mohs surgery is accurate and effective at treating all sizes of skin cancers, including large, recurrent, and aggressive cancers in challenging areas. This makes it an excellent treatment option for complex cases.

Reduced Risk of Recurrence

The meticulous technique of examining the tissue removed in real-time, mapping, and tracking ensures all cancerous cells are removed. This technique reduces the risk of leaving behind any remaining cancer cells, thereby reducing the chances of recurrence. You won’t need any repeat surgeries or additional interventions.

benefits of mohs

What Are the Side Effects of Mohs Surgery?

Most people who undergo Mohs surgery have different experiences after the surgery. Some experience complications and side effects, while others don’t. Some Mohs surgery side effects and complications occur days or weeks after the procedure, while others occur immediately. Complications and side effects also vary in severity depending on the size and location of the wound.

Common Mohs surgery side effects include the following:

1. Bleeding

Bleeding will occur during surgery as the surgeon cuts away your tissue. It may continue briefly after the surgery before you start healing. Your doctor will give you instructions on managing the bleeding, such as applying pressure to the area.

2. Pain and Swelling

After the local anesthesia wears off, you will experience pain and discomfort around the surgical site. Most surgical procedures, including Mohs surgery, leave patients with mild to excessive swelling. The swelling goes away a few days or weeks after the surgery.

3. Scarring

Scarring can’t be avoided, even if the doctor tries to remove as little healthy tissue as possible. To minimize the time it takes for the scars to disappear, ensure you follow the scar management recommendations from your doctor. They include protecting the site from sunlight and using topical treatments. You can use reconstructive techniques to minimize scarring, but it may take several months to see the results.

If the surgery is performed near sensitive areas like eyes, eyelids, ears, lips, or nose, it can impact their appearance and functionality.

side effect of mohs

4. Dehiscence

Dehiscence is the opening of the surgical wound. It can occur after any surgery, including Mohs, due to inadequate wound healing, the tension on the excised site, and other factors. It can lead to delayed healing, tissue exposure, higher infection risk, and other complications.

You can minimize the risk of dehiscence by following the Mohs surgeon’s postoperative instructions and following good would care practices.

5. Partial or Full Necrosis

Necrosis occurs when the tissue at the wound site dies. Partial necrosis is the death of some parts of the tissue, while full necrosis is complete tissue death. Necrosis can be caused by excessive tissue trauma, infection, compromised blood supply to the site, etc.

6. Infection

Infection can occur during and after the surgery when bacteria and other microorganisms enter the surgical site. It is caused by poor wound care, such as improper cleansing and dressing. It can also be caused by a compromised immune system due to certain medications or pre-existing infections.

These infections can worsen the other side effects of Mohs surgery and complications of the procedure, including increased pain and discomfort, delayed healing, and dehiscence. Infection can also lead to abscess formation or spread beyond the surgical site.

7. Nerve Damage

During tumor and tissue removal, the surgeon can sever superficial nerves. The area may become numb, tingly, or feel different temporarily or permanently. If the tumor is deep under the skin, severing nerves can result in loss of muscle control.

Most cases of nerve damage resolve over time as nerves regenerate and restore sensation. But it can also be permanent.

8. Allergic Reactions

Some patients may break out into a skin rash after Mohs surgery. The rash can result from an allergic reaction to the surgical tape covering the wound. Though rare, some people can have allergic reactions to Lidocaine, the standard local anesthetic used for Mohs surgery. It can lead to redness, irritation, or swelling at the injection site.

9. Recurrence

Despite its high cure rate, the cancer can recur after Mohs surgery. You should get skin examinations regularly to catch it at its earliest stages if it recurs.

10. Delayed Healing

The surgical site can take longer to heal due to factors like medical conditions and poor blood circulation as you heal. It increases the risk of infection and contributes to more noticeable scarring. If the surgery was performed in a sensitive area like near joints or mouth, delayed healing affects its functionality longer. It can also affect an individual body image and self-esteem.

However, it is important to note that these side effects of Mohs surgery are infrequent. According to a study, out of 20,821 Mohs surgeries, only 149 had adverse events (0.72%), and only 4 had serious events (0.02%). The most common adverse events in order are:

  • Infections
  • Dehiscence
  • Partial or full necrosis
  • Bleeding and hematoma

mohs side effects

What Should You Do When You Experience the Mohs Surgery Side Effects?

If you experience the side effects of Mohs surgery, you should take the appropriate steps to manage and address them. Here are some tips and best practices for managing them.

  • Take medications as prescribed.
  • Stay hydrated.
  • Follow the surgeon’s postoperative care instructions.
  • Keep the surgical site clean and dry.
  • Apply ice packs to the affected area to reduce swelling and pain.
  • Avoid strenuous activity or heavy lifting for a few days after the procedure.
  • Keep the wound clean and dry to prevent infection.
  • Protect the site from direct sunlight.
  • Eat a balanced diet.
  • Rest as much as possible to allow your body to heal.
  • Don’t miss follow-up appointments.

Proper side-effect and complication management promotes healing, reduces discomfort, and minimizes complications.

When Should You Seek Medical Advice After Mohs Surgery?

You should seek medical advice after Mohs surgery if you notice the following:

  • Signs of infection like redness, swelling, warmth, pain, or pus-like drainage from the site.
  • Bleeding from the wound that does not stop or starts up again after stopping.
  • A feeling of tightness or pressure around the wound.
  • Signs of an allergic reaction, include rash, itching, or difficulty breathing.
  • Fever or other signs of illness.
  • Worsening pain that pain medications can’t relieve.
  • Delayed healing
  • Worsening swelling or bruising

You should also seek medical advice if you have any questions, concerns, or uncertainties regarding your Mohs surgery recovery. They can guide and reassure you.

mohs medical advice

Where to Get Mohs Surgery in LA

Mohs surgery is a technique for removing skin cancer that involves cutting away the tumor in layers. It is highly effective and offers benefits like minimal scar formation, reduced risk of recurrence, and maximal tissue preservation. It is also suitable for complex skin cancer cases.

However, Mohs surgery side effects may exist. It can lead to complications and side effects like bleeding, scarring, pain, necrosis, nerve damage, and delayed healing. If you experience these side effects, you should take steps to manage them. But if they show signs of infection, excessive bleeding, worsening pain or swelling, and the other signs we have discussed, you should seek medical advice.

If you are in Los Angeles, you can get your Mohs surgery at BHSkin Dermatology. At BHSkin Dermatology, our award-winning dermatologists are the best in handling such a delicate procedure with minimal side effects. Visit us at our Glendale or Encino clinic, or use our virtual portal for your initial consultation to determine if surgery is the best treatment option. Book your appointment today!


Author: Don Mehrabi

Dr. Don Mehrabi is a board-certified dermatologist providing medical care to patients in the Beverly Hills, California area at BH Skin Dermatology.

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