Fatigue and anemia are common symptoms of chronic diseases like hidradenitis suppurativa (HS), also called acne inversa. HS causes small, painful lumps to form under the skin. Anemia is a well-known cause of fatigue, but it can also be a sign of disease activity in HS and other inflammatory diseases. Learning more about the connections between anemia, fatigue, and HS can help people with HS to better address these issues and improve their quality of life.

What Is Anemia?

Anemia occurs when the blood is unable to carry enough oxygen to meet the body’s needs. When someone has anemia, they have low levels of hemoglobin in their blood. Hemoglobin is the protein that red blood cells (RBCs) use to carry oxygen throughout the body.

Research tells us that the prevalence (how common a condition is) of anemia in HS is high. As many as 40 percent of people with HS have anemia, with men and African American individuals having the greatest increased risk of developing anemia with HS. Other studies have shown that people with HS are about six times more likely to have anemia than the general population. Anemia may also be a mark of worsening disease activity in those with severe HS.

Symptoms of Anemia

Symptoms of all types of anemia can include:

• Fatigue (most common symptom)
• Weakness
• Shortness of breath
• Dizziness or lightheadedness
• Fast or irregular heartbeat
• Headaches
• Pale or yellowish skin
• Cold hands and feet
• Chest pain

The more severe the anemia is, the more symptoms a person will have. People with very mild anemia may not experience any symptoms at all.

Iron-deficiency anemia (IDA) can cause additional symptoms including:

• Sore or inflamed tongue
• Brittle nails
• Poor appetite
• Pica (eating ice, clay, chalk, or other nonfood items)

How Is Anemia Diagnosed?

Anemia can only be diagnosed with a blood test. A complete blood count is used to measure hemoglobin levels and the number of red blood cells in the blood. Anemia is defined as having a hemoglobin level less than 13.5 grams per deciliter in men or 12 in women. Additional tests can help diagnose the type and cause of anemia, including blood tests for iron, folate (folic acid or vitamin B9), and vitamin B12 levels.

What Causes Anemia?

Anemia has several different causes, but the most common types of anemia seen with HS are iron-deficiency anemia and anemia of chronic disease (ACD).

Iron-Deficiency Anemia

IDA occurs when iron is not available to make hemoglobin for new red blood cells. This condition can occur due to not eating enough foods with iron, poor iron absorption in the gut, or blood loss. Researchers have also found that iron deficiency may make HS and other inflammatory skin diseases worse.

Iron levels and iron availability can be affected by chronic inflammation. IDA is common in women of childbearing age — menstrual bleeding, pregnancy, and breastfeeding can all contribute to IDA in women.

Also, recent research has shown that most people with HS have abnormal iron metabolism (chemical reactions that maintain iron) that can lead to iron deficiency.

Anemia of Chronic Disease

ACD — also called anemia of inflammation — occurs in people with chronic illnesses. Diseases like HS that cause chronic inflammation are frequent causes of ACD. Autoinflammatory conditions and autoimmune diseases, such as spondyloarthritis and rheumatoid arthritis, are also common causes of ACD.

ACD prevents normal RBC production in several ways. Chronic inflammation can shorten the life span of RBCs. Chronic inflammation can also cause iron to accumulate in macrophages (white blood cells that destroy aging red blood cells), making it unavailable to create new hemoglobin.

Chronic inflammation can decrease iron availability by increasing levels of hepcidin (a hormone that controls iron storage and transport) due to high levels of proinflammatory cytokines — chemical messengers that promote inflammation.

The latest research shows that hepcidin levels help to identify the cause of anemia in people with HS. Additionally, other research from the American Journal of Clinical Pathology has shown that higher hepcidin levels indicate worse disease severity in HS. (HS is divided into three stages, based on how severe it is, called Hurley stages.)

Other Types of Anemia

Other types of anemia can occur with HS, including pernicious anemia and hemolytic anemia, which are rare but dangerous.

A deficiency in vitamin B12 causes pernicious anemia. In this type of rare anemia, antibodies from the immune system prevent the normal digestion of vitamin B12, which is needed to produce red blood cells.

Hemolytic anemia occurs when the body destroys red blood cells faster than it makes them. Autoimmune diseases can cause hemolytic anemia, such as Crohn’s disease — a possible comorbidity (conditions that occur together) of HS. Hemolytic anemia can also be a side effect of some medications. The antibiotic dapsone, sometimes used to treat HS, is known to cause hemolytic anemia in certain people.

How Does Anemia Affect myHSteam Members?

Some myHSteam members have mentioned that they have severe IDA with their HS. One member said, “I’m so anemic I have to get iron infusions every other week.”

Other myHSteam members have shared their experiences with fatigue and HS. Whether due to anemia or other causes, many people with HS live with fatigue. One member asked, “Has anyone experienced chronic fatigue with HS? I feel like I’m always exhausted.” Another member shared, “I can’t stand the fatigue and body aches.” And another team member lamented, “Fatigue is my biggest struggle, still.”

At least one member did not know that HS could cause fatigue. They said, “Up until today, I didn’t realize my fatigue could be caused by this condition, as my doctor never told me.”

Various members have noticed an association between worsening fatigue and flare-ups of HS lesions, which are known to go hand in hand with anemia. One member said, “I’m noticing that right before I have a flare-up, I have other symptoms like fatigue and body aches.” Another member shared, “These flares give me extreme fatigue.”

How Is Anemia Treated?

Anemia treatments vary based on the cause, but in people with HS or other inflammatory conditions, it is also important to treat the underlying chronic disease.

Blood Transfusion

Severe anemia that is potentially life-threatening may require a blood transfusion. A transfusion of red blood cells is typically only used to treat extremely low hemoglobin levels (less than 7, about half of the normal minimum hemoglobin level) or severe anemia that has not responded to other treatments.

Iron Replacement

IDA can often be treated by simply getting more iron from your diet or from iron supplements. To maintain healthy iron levels, eat foods that are rich in iron, including:

• Meat
• Seafood
• Legumes (beans, peas, peanuts)
• Dark leafy green vegetables (spinach, greens)
• Dried fruit (apricots, raisins)
• Foods fortified with iron (cereal, bread, pasta)

Eating foods rich in vitamin C can also improve iron absorption:

• Citrus fruit
• Broccoli
• Peppers
• Strawberries
• Melons
• Tomatoes

Eating a proper diet can help prevent iron deficiency, but sometimes iron supplements may be needed to restore healthy iron levels. Intravenous iron can also be used to treat iron deficiency, especially in people who cannot tolerate or absorb oral iron supplements. Before taking any supplements, ask your doctor to explain the risks and benefits.

Vitamin B12 and Folate

Supplemental vitamin B12 and/or folate may be used to treat anemia in people with deficiencies in these vitamins. People who cannot absorb vitamin B12 well, such as those with pernicious anemia, need vitamin B12 injections to raise their B12 levels.

Erythropoietin-Stimulating Agents

In some cases, medications called erythropoietin-stimulating agents may be used to increase RBC production in people with low levels caused by chronic inflammation or from cancer or chemotherapy.

Treating Underlying Inflammation

Treating the underlying cause of inflammatory disease is an important part of managing ACD. Certain biologic drugs used in the treatment of HS may also help improve anemia.

Anti-tumor necrosis factor biologic drugs help stop inflammation. They are used to treat HS and other diseases. Examples of these medications are adalimumab (Humira) and infliximab (Remicade). Anti-tumor necrosis factor biologic drugs have been shown to improve anemia in people with inflammatory bowel disease, ankylosing spondylitis, rheumatoid arthritis, and psoriatic arthritis.

Talk to Your Doctor

If you are concerned about anemia or fatigue, talk to your dermatologist or other health care provider about possible causes and interventions. Simple blood tests may help identify the source of your fatigue and guide treatment options.

Treating anemia may or may not improve your fatigue. Getting HS symptoms and flares under control is likely the best way to improve fatigue and help prevent anemia.

Find Your Team

On myHSteam, the social network for people with HS and their loved ones, more than 24,000 members come together to ask questions, give advice, and share their stories with others who understand life with HS.

Are you experiencing anemia or fatigue with your HS? Share your story in the comments below, or start a conversation by posting on your Activities page.