Zebra Awareness: Rare Disease Day

Medical students are taught to "think horses, not zebras" when diagnosing
a condition. In other words, consider first the most likely condition. In people
of size, this means that weight is often blamed and other explanations ignored.
Weight bias keeps many conditions from being diagnosed in high-BMI people.

February 29th is Leap Day, otherwise known as Frederick's Birthday to music nerds everywhere (think Pirates of Penzance ─ "...A paradox, a paradox, a most ingenious paradox....").

More importantly, today is also "Rare Disease Day," a day to call for more attention and research into rare serious illnesses. The National Organization of Rare Disorders states that in order to be a rare disease, there have to be fewer than 200,000 affected individuals in the United States. As one news release states:

Of the 7,000 diseases classified as “rare,” only about 400 have an effective treatment. Research of diseases that affect a tiny percentage of the population is woefully underfunded, say advocates from the National Organization for Rare Disorders (NORD), the national sponsor of Rare Disease Day.

Today this blog focuses on rare illnesses in honor of Rare Disease Day, but especially those that get ignored or shrugged off simply because the sufferers are fat. Sadly, weight bias plays a significant role in the under-diagnosis of and under-attention to many conditions in high-BMI people, and rare illnesses are no exception.

To raise awareness of rare conditions impacted by weight bias, here are a few brief descriptions.

Numerically Rare 

Dercum's Disease, sometimes known as Adiposis Dolorosa or Painful Fat Disorder, is a Rare Adipose Disorder (RAD). In this condition, small fatty growths (lipomas) occur under the skin and cause significant pain, perhaps by pressing on nearby nerves. These growths usually occur mainly on the trunk, upper legs, and upper arms. Swelling and significant weight gain are common in people with Dercum's Disease. Other symptoms can include fatigue, weakness, easy bruising, headaches, stiffness, irritability, depression, and memory or concentration issues.

Madelung's Disease, also known as Multiple Symmetric Lipomatosis (MSL), is another Rare Adipose Disorder. It also involves small fatty growths (lipomas) but these occur primarily on the neck, shoulders, upper arms, and upper trunk, while the rest of the body is average-sized or even thin. Its onset is characteristically later in life, between 30-60 years. Although it is most often found in alcoholic men of Mediterranean descent, it can be found in non-alcoholic women too.

Cushing Syndrome is an endocrine disorder caused by too much cortisol. It can result from external sources (like long-term use of steroids for another medical condition) or internal sources (a benign pituitary tumor causing the adrenal glands to produce too much cortisol). It results in weight gain, a highly rounded face and upper body, and truncal fat, while the arms and legs are typically average-sized. Thin purple streaks may appear on the skin, and the skin can be very fragile. Acne, facial hair growth, irregular periods, thinning scalp hair, high blood pressure, high blood sugar, and osteoporosis are common sequelae.

Intracranial Hypertension is an extremely debilitating disorder that is more common among women of size, although it can happen in people of any size. It is caused by a build-up of pressure within the skull due to too much cerebral spinal fluid. It results in massive, unrelenting headaches. In addition, it often results in vision changes and pulsating tinnitus. It can mimic the symptoms of a brain tumor, which is why it is sometimes called Pseudotumor Cerebri, though this is considered an outdated term by many now.

Autoimmune Thyroiditis is a chronic inflammatory condition of the thyroid, also called Hashimoto's Disease, in which the body's immune system periodically attacks the thyroid. Its symptoms commonly include unexplained weight gain, intolerance to cold, hair loss, menstrual irregularities, fatigue, and dry skin. It may exist as a condition on its own but often exists in conjunction with other conditions like PCOS and lipedema. (Although NORD lists this as a rare disorder, I think it is far more common than believed.)

Ehlers-Danlos Syndrome is a "group of hereditary connective tissue disorders characterized by defects of the major structural protein in the body (collagen)." Collagen helps hold together, strengthen, and provide elasticity to body tissues. There are several sub-types, with symptoms ranging from fairly mild to severe. Many people with lipedema (see below) have Ehlers-Danlos Type III, or hypermobility. Symptoms include lax joints, chronic joint pain, frequent tendinitis, and early development of osteoarthritis. Fragile tissues, including skin and blood vessels, are also common, leading to problems such as easy bruising and poor wound healing.

Hidradenitis Suppurativa is a skin condition that commonly presents as swollen, painful skin lesions in particular areas of the body (including armpits, groin, perineum, and breasts). It can begin as blocked or infected hair follicles or sweat (apocrine) glands. A hard, boil-like abscess filled with pus forms. In severe forms, these can form clusters of lesions and significant scarring can occur.

Acanthosis Nigricans is a skin condition characterized by darkened coloration and a "velvety" texture. It usually is seen in skin fold regions, especially in the groin area, under the arms, or on the neck. It is associated with insulin resistance, so it's common in women with Polycystic Ovarian Syndrome (PCOS). Although AN is usually relatively benign, there is a more aggressive form that can be associated with tumors.

Not Numerically Rare

There are other disorders that are commonly underdiagnosed in fat people because of weight bias. Even though these don't meet the 200,000 cases cut-off, these conditions tend to be chronically under-researched, under-funded, and under-treated, just like rare diseases.

And just like those who have rare diseases, many of these people face devastating medical problems, difficulty getting a diagnosis, difficulty finding information about their condition, and limited treatment options. Many feel very alone in facing their condition, especially when their weight is constantly blamed for their symptoms and they are continually given weight-loss prescriptions that may make things worse.

So even though the following conditions aren't truly "rare," the weight bias surrounding them means that many get treated like rare conditions do. Therefore I am including them as an addendum to my list.

Lipedema/lipoedema is called a "Rare Adipose Disorder" too, just like Dercum's and Madelung's Diseases, even though lipedema's incidence is estimated at about 11% of the population. The National Institute of Health's Genetic and Rare Diseases Information Center website does list lipedema on its site, though with an asterik stating that lipedema is not a rare disease.

However, as we recently discussed, weight bias has impacted the diagnosis and treatment of lipedema significantly. As one study put it:

This frustrating genetic disorder of fatty deposition is not particularly rare, but is rarely diagnosed because clinicians fail to recognize it.

Lipedema is characterized by a symmetrical enlargement of the lower body (waist to ankles) and sometimes the arms. It is bilateral (on both sides) and typically does not involve the feet. It tends to get worse at times of hormonal changes (puberty, pregnancy, menopause, gynecological surgery) and can cause sudden unexplained weight gains that do not respond to diet and exercise. In later stages, severe lymphedema can also develop, mobility can be affected, and skin infections can occur.

Polycystic Ovarian Syndrome (PCOS) is estimated to affect about 5-10% of the population, and can greatly impact a woman's hormones, menstrual cycle, fertility, and metabolism. Other side effects can sometimes include acne, hirsutism (unwanted hair growth on the face or body), alopecia (hair loss on the head), and cysts on the ovaries. Insulin resistance is deeply entwined with most cases, so there is a strong tendency towards weight gain, as well as diabetes and high blood pressure.

PCOS has become more recognized by the medical establishment in the last few years. Even so, many women with PCOS still go undiagnosed for years, receive substandard or shaming treatment, or are only given lectures about diet and exercise instead of being offered a wider range of care options. PCOS is certainly under-researched, with most of its research focusing narrowly on fertility and menstruation rather than whole-life health implications, and its research and treatment is quite impacted by weight bias.

Closing Thoughts

These are but a few of the rare diseases that can impact high-BMI people; there undoubtedly are many more. If you have others you'd like to share, please put them in the comments section.

Of course, there are many rare diseases that deserve attention and research dollars. Sadly, weight bias means that many of the above conditions are losing out in the race for research money, and that many people of size are not being appropriately treated for these conditions.

It's time to change that.