Doctors and researchers have found that certain health conditions may raise your risk of melanoma skin cancer. In some cases, treatments for a health condition can increase the chances of melanoma, or vice versa. Some conditions may appear similar to melanoma and need to be ruled out during the diagnosis of melanoma.

In this article, we’ll discuss seven conditions that may be related to melanoma or melanoma treatment.

1. Psoriasis

Psoriasis is a skin disease caused by an overactive immune system. Normally, skin cells grow and shed from your body in a one-month cycle. Skin inflammation in psoriasis speeds this cycle up to a few days. The cells begin piling up on your skin’s surface, which creates plaques or lesions.

Psoriasis plaques are typically found on the scalp, elbows, and knees. Depending on your skin tone, they can be red, pink, gray, or brown. Plaques may be covered in silver or gray scales.

Some studies have looked into the genetic link between psoriasis and melanoma. One study of genes found that people who had genetic mutations (changes) associated with a higher risk of developing psoriasis had a 69 percent greater chance of developing melanoma skin cancer.

Researchers believe that certain psoriasis treatments may also increase the risk of developing melanoma. Light therapy uses ultraviolet (UV) radiation to slow skin cell growth and control psoriasis plaques. However, UV rays are also a well-known cause of melanoma. Other psoriasis treatments that target the immune system may also contribute to the risk of melanoma.

2. Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that affects the joints. Specifically, the immune system mistakenly attacks the tissue that lines and cushions the joints. People with RA experience joint pain, swelling, or stiffness — especially in the small joints in the wrists, hands, and feet.

Research shows that people with RA are at a higher risk of developing several types of cancer — including melanoma. One study from The Lancet of more than 250,000 people found that those with RA have a greater risk of melanoma compared to those without RA.

RA is typically treated with medications that suppress aspects of the immune system to stop it from attacking the body. Some research suggests that certain RA treatments may raise the risk of melanoma.

3. Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) involves long-term inflammation along the digestive tract. There are two types of IBD — ulcerative colitis and Crohn’s disease. Both cause abdominal pain, weight loss, fatigue, and diarrhea.

A study from Clinical Gastroenterology and Hepatology found that IBD is associated with a 37 percent higher risk of melanoma skin cancer. Another study from Mayo Clinic Proceedings looked at 109 people with IBD who were treated with immunomodulators — medications that modify the immune system. The researchers found that people treated with immunomodulators had a greater risk of melanoma compared to those who weren’t treated.

4. Parkinson’s Disease

Neurological conditions like Parkinson’s disease (PD) may also increase the risk of melanoma. PD is caused by the breakdown or death of nerve cells in the brain that control movement. These cells normally make a chemical called dopamine. Without enough dopamine, your nerve and muscle cells can’t function properly. This is why many people with PD experience tremors, muscle stiffness, or trouble with coordination and balance.

PD seems to lower the risk of developing most cancers — except melanoma skin cancer. Many large studies have found that melanoma is more common in people with PD compared to the general population. Research from the journal Neurology showed that PD is associated with a twofold increased risk of melanoma. Results suggested that men with PD are twice as likely to develop this skin cancer, while women with PD are 1.5 times as likely.

Scientists have recently discovered a potential link between PD and melanoma. Alpha-synuclein is a protein typically found in nerve cells that make dopamine. In PD, these proteins are abnormal and form clumps that interfere with the brain’s function.

Melanoma cancer cells also make alpha-synuclein proteins. One study found that stopping melanoma cells from making these proteins may slow cancer growth and spread.

It’s important to note that PD doesn’t cause melanoma, and melanoma doesn’t cause PD. Instead, both diseases are linked to higher alpha-synuclein protein levels. PD and melanoma also share other risk factors, including increased age and exposure to toxins.

Read more about the causes and risk factors for melanoma, which include sunburns and a family history of melanoma.

5. Endometriosis

Endometriosis develops when tissue that normally lines the uterus grows on or around organs in the pelvis and abdomen. As many as 10 percent of women ages 15 to 44 are diagnosed with endometriosis. This condition can cause severe pain, abnormal menstrual cycles, and infertility.

Several studies have found that endometriosis significantly increases the risk of melanoma. One study from the Archives of Internal Medicine followed French women with endometriosis for 12 years. The study authors reported that endometriosis was associated with a 62 percent higher risk of melanoma.

Endometriosis and melanoma also share several risk factors, including having fair skin, red hair, and more moles on the skin. Women who have had melanoma also appear to be at an increased risk of endometriosis. Additionally, research shows that both diseases share a genetic component. Many gene changes involved in endometriosis are also found in melanoma.

6. Aplastic Anemia

All cancer treatments come with side effects. Melanoma treatments — like immunotherapy, chemotherapy, and radiation therapy — can all lead to aplastic anemia as a complication. This serious blood disorder occurs when your body can’t make enough new blood cells.

Aplastic anemia can cause:

• Easy bleeding and bruising
• Longer, more frequent viral infections
• Fatigue
• Dizziness
• Shortness of breath

Multiple case reports have found that treatment with immune checkpoint inhibitors (ICIs) can lead to aplastic anemia. ICIs may be used to treat both early and advanced melanoma. Although aplastic anemia is a rare complication, it’s still important to note that it can occur.

7. Other Skin Cancers

When diagnosing melanoma, your doctor or dermatologist (skin specialist) will rule out other types of skin cancer. Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are much more common than melanoma. However, all three cancers tend to develop on skin exposed to sunlight (UV light) and can look similar to one another. If you’ve had BCC or SCC, you have a higher risk of developing melanoma.

BCC can cause open sores (ulceration) that ooze or form crusts, or small pink or red bumps with black, brown, or blue areas, depending on your skin tone. SCC tends to form wart-like growths, rough patches of skin, and open sores.

It’s important to note it’s possible to have these health conditions without ever developing melanoma and to have melanoma without having these conditions. If you’re worried you have a high risk of developing melanoma, talk to your doctor.

Find Your Team

MyMelanomaTeam is the social network for people with melanoma and their loved ones. On MyMelanomaTeam, members come together to ask questions, give advice, and share their stories with others who understand life with melanoma.

What health conditions are you living with in addition to your melanoma? Share your experience in the comments below, or start a conversation by posting on your Activities page.