Adiposis dolorosa, also referred to as Dercum’s disease, is a rare, chronic condition characterized by the presence of multiple painful lipomas—benign tumors of fat—within the subcutaneous fat. Lipomas are usually soft, round and painful when touched. They can occur anywhere in the body, but they are best seen on the trunk, arms and thighs.

What makes adiposis dolorosa different from regular lipomas is the persistent and often debilitating pain that comes from these fatty growths. This pain can be dull and achy or sharp and burning, continuous or intermittent, often provoked by touch, pressure or for no apparent reason. Often, the condition presents with fatigue, obesity and psychological symptoms, such as depressive or anxiety-like symptoms.

In the past, adiposis dolorosa was grouped with other conditions like lipedema, but now doctors consider it a separate condition. It mainly affects adults, with a ratio of women to men being 5:1, and it’s most common in people between 35 and 60 years old. Adiposis dolorosa has been characterized since the late 1800s, but the cause is still unknown. Because of the overlapping complaints with other disorders and lack of public knowledge, it is frequently misdiagnosed or underdiagnosed, making it difficult to identify its actual prevalence.

Doctors don’t know exactly what causes adiposis dolorosa, which makes it hard to create clear ways to diagnose and treat it. Nevertheless, based on clinical experience, case studies and preliminary evidence, researchers and clinicians have suggested a number of theories. The proposed mechanisms include genetic, hormonal, neurologic, inflammatory, and lymphatic mechanisms.

1. Potential Genetic Mechanisms: Some case studies have noted a familial component to adiposis dolorosa in which more than one first degree relative has also been diagnosed with this condition. This suggests that there may be a possible autosomal dominant inheritance; however, there are no studies that have identified a specific gene mutation. Depending on the variations of the condition, there may be distinct subtypes of the disease, and some of these subtypes may influence underlying genetic components to a higher degree than others.
2. Hormonal or Endocrine Dysregulation: Hormonal or endocrine dysregulation, especially of estrogen and cortisol, has been postulated to have a role in the development or worsening of adiposis dolorosa because the condition often arises or worsens at times of hormonal transition such as childbirth, menopause, or after hysterectomy. These observations support a role for hormonal or endocrine dysregulation. Hormonal dysregulation may influence abnormal fat deposition, pain sensitivity, or the development of lipomas.
3. Neurological Dysfunction: A second significant theory focuses on the peripheral nervous system and how it processes signals of pain.  It is typical for patients with adiposis dolorosa to have dysesthesia, which is hypersensitivity to touch and pressure. This may be due to core abnormalities from entrapment caused by fatty tissue or an abnormal positive feedback mechanism related to pain modulation. As a result of these neuroplastic changes it is possible to suffer chronic pain associated with the disease. 
4. Inflammatory Mechanisms: Some researchers propose that chronic low-level inflammation within the adipose tissues is a contributing factor.  Chronic low-level inflammation could promote fibrosis, irritating nerves and/or increasing sensitivity to pain.  While lacking definitive evidence to confirm chronic inflammation in adiposis dolorosa, we are now cognizant of the potential for syndrome development from potential cytokine release associated with adipose tissue, an indwelling endocrine and inflammatory organ.  
5. Lymphatic Dysfunction: There is increasing speculation surrounding the role of the lymphatic system in adiposis dolorosa.  Lymphatic dysfunction could result in impaired fluid drainage and increased fat deposition.  Eventually lymphatic dysfunction leads to pressure against surrounding nerve networks and worsens pain perception. Some patients experience swelling and heaviness of their limbs which supports this emerging theory.  
6. Autoimmune Involvement (Speculative): Some experts have suggested that adiposis dolorosa may have an autoimmune component, in which the immune system erroneously attacks healthy tissues including fat and nerves. However, there is no definitive evidence that indicates this condition is linked to abnormal immune function or autoimmune diseases. Though this is purely speculative, it demonstrates a need to investigate the disease’s underlying mechanisms more adequately..

While no one knows the specific causes of adiposis dolorosa, several risk factors have been associated with its development. Knowing the risk factors can help us understand how adiposis dolorosa develop.

1. Gender and Hormones: Adiposis dolorosa occurs much more frequently in women than in men, especially overweight women who are experiencing hormonal changes—specifically during perimenopause and menopause. The heavy female predominance in this disease reinforces the idea that hormones may influence the development or progress of the disease.
2. Obesity: There are strong associations between obesity and adiposis dolorosa. Almost all individuals with the disorder are either overweight or obese, although it is still unclear if excess weight is a contributor to the disease, or if it is a product of the disease. Having more adipose tissue may influence the growth of lipomas and may result in pressure on the nerves, which may increase pain.
3. Family History: There is also some evidence of family history impacting adiposis dolorosa. For some individuals, having an immediate family member with adiposis dolorosa may be associated with being diagnosed, pointing to the potential for some hereditary component.
4. Past Trauma or Surgical Events: Some people can experience symptoms after an injury or surgical operation. For this reason, researchers considered if trauma could initiate lipoma formation or activate pain pathways in biologically susceptible people. 
5. Autoimmune or Inflammatory Processes: Although none has been confirmed some speculate autoimmune or inflammatory processes may be contributory, especially in those who have fibromyalgia or rheumatoid arthritis. It is possible these comorbidities have similar pathways that provide some explanation for the illness. 

Adiposis dolorosa can manifest differently from person to person, but the most consistent characteristic is chronic pain in fatty tissue. The pain can be constant or intermittent, and may get worse with touch or pressure, within the emotional spectrum of stress and fatigue, or from weather changes.

• Painful Lipomas: Painful lipomas are the main symptom of painful adiposis. The lipomas are almost always soft and are movable, but they are different from ordinary lipomas in that they are usually painful and tender with pain sometimes described as sharp, burning, or aching.
• Widespread Pain: Some individuals may experience generalized pain that involves more than just the fatty lumps in the areas of soft tissue, joints, and muscle similar to fibromyalgia.
• Fatigue: People often experience persistent fatigue as it relates to sustained pain, poor quality of sleep, and chronic emotional tension related to the pain.
• Cognitive and Emotional Symptoms: Many patients report symptoms of brain fog with poor attention, and emotional disturbances including anxiety or depression which appear linked to the persistent pain.
• Sleep Disruption: Pain can interfere with the ability to enjoy restorative sleep which can create insomnia or non-restorative sleep. Insufficient sleep can lead to increased levels of fatigue.
• Swelling and Fluid Retention: Some people have swelling in their limbs that we can assume is due to some sort of lymphatic failure or retention of fluid due to the fatty deposits.
• Unexplained Weight Gain: Many individuals may also experience unexplained weight gain in the upper arms, legs, and trunk. Individuals may also generally have difficulty with weight loss in the same areas despite attempts to control their weight.
• Stiffness in the morning: Many individuals will have stiffness from lying down, usually this is most noticeable in the morning. There is frequently improvement with movement.
• Breast Involvement: Some individuals may experience painful fatty deposits in their breasts which will need to be differentiate from a non-painful lump of a cancerous origin.

Adiposis dolorosa is usually diagnosed with a careful clinical history and physical examination. Since there are no definitive laboratory tests or imaging studies to establish the diagnosis, it typically resembles a diagnosis of exclusion, with other possible causes of painful nodules ruled out.

Diagnostic criteria may include:

• Multiple painful lipomas
• History of chronic pain for over three months
• Other exclusionary conditions such as fibromyalgia, lipedema or panniculitis
• Typical female middle-aged onset
• Other symptoms such as fatigue, cognitive problems and mood disorders

Diagnostic Tools and Supportive Tests:

Imaging: Your doctor may do an MRI or ultrasound to help differentiate lipomas from other soft tissue masses and to identify the extent of tissue involvement.

Biopsy: Biopsies are not usually necessary but sometimes done to rule out cancer if there is a concern of malignancy.

Lab Tests: Tests can show mild elevations in cholesterol, and/or mild elevation in ESR (a test that checks for inflammation in the body).

Hormonal tests: Cortisol explanation and thyroid function tests, may be useful to exclude Cushing’s syndrome and hypothyroidism; both conditions can also present with similar symptoms.

At present, there is no known cure for adiposis dolorosa. Treatment is directed largely at symptoms, with the focus to relieve pain and improve quality of life and additional related symptoms associated with fatigue, depression, and anxiety. Multiple disciplines are likely to provide the best results. 

General Measures

• Weight Control: Although not curative, reaching and maintaining a healthy weight may relieve some of the stress on the body and assist with symptom control.
• Psychological Therapy: Therapy can assist the individual to relieve some of the emotional stress associated with living with chronic pain and how it affects daily life.

Specific Treatment Approaches:

• Pain Management: Chronic pain is the most debilitating condition of adiposis dolorosa. You may use a combination of medications and non-drug treatments. The medications include:
  • NSAIDs: Over-the-counter medications like ibuprofen or naproxen are used to treat mild to moderate pain. 
  • Opioids: In cases of severe pain, opioids may be used, but are fully engaged through a doctor or specialist, or prescriber, when used because of the potential for dependence. 
  • Anticonvulsants: Drugs like gabapentin or pregabalin are used to treat nerve pain. 
  • Antidepressants: Tricyclic antidepressants (for example: amitriptyline) or SNRIs (for example: duloxetine) relieve both pain and mood disorders. 
  • Topical Agent: Lidocaine patches, and if you have localized pain, lidocaine injections may be used to treat the specific pain area
• Surgical Removal of Lipomas: In some cases, if lipomas are painful, significantly impact function or mobility in some other way, you may have surgical excision. If the surgery does affect pain, other lipomas may form, you will still have the disease. 
• Liposuction: Liposuction may be a treatment that could help patients with significant amounts of lipomas. The goal is to decrease body fat, therefore reducing pain. Some patients experience a significant improvement in quality of life while others feel relief from the excessive body fat, while it may come back. Individual results vary.
• Physical Therapy and Exercise: Low-impact activity, such as walking, swimming, or light stretching, can increase mobility, circulation, and mood. Physical therapy can also reduce stiffness. However, vigorous or strenuous activity may worsen symptoms. 
• Psychological Support: Due to its painful and chronic nature, adiposis dolorosa may have an impact on mental health. Psychological support, including cognitive behavioral therapy (CBT), may improve coping techniques, reduce anxiety, and assist with depression.
• Nutritional Support: While diet alone will not treat the condition, anti-inflammatory eating habits may support overall health and well-being. A diet high in fruits, vegetables, whole grains, and lean protein as well as low in sugar and processed foods is advised.
• Complementary Therapies: Some patients may find benefit from complementary therapies such as:
  • acupuncture
  • massage therapy
  • herbal remedies

Despite minimal scientific evidence, this modality may provide some relief of symptoms and to manage stress to some degree.

• Deoxycholic Acid Injections: Deoxycholic acid is an injectable medicine that destroys fat and absorbs the fat. This medication is commonly provided for cosmetic fat destruction. It is currently being investigated for efficacy in treating adiposis dolorosa, but significant studies are awaited to establish its efficacy in this disorder. 
• Transcutaneous Electrical Stimulation: Potentially an option for some persons with Dercum’s disease is transcutaneous frequency rhythmic electrical stimulation to fatty tissue. Significant potential has been established for high frequency electrical stimulation to reduce pain and improve quality of life. It is not invasive and is safe for this purpose.

Adiposis dolorosa is a rare condition characterized by painful lipomas, fatigue and psychologic symptoms, primarily in middle-aged females. Its etiology remains unknown but most likely have inciting factors from genetics/hormones or nerve sensation related. 

Diagnosis is difficult and there is currently no cure; however, many patients may find there are several ways to manage symptoms through a team-care approach of primary care physicians, pain specialists, mental health care professionals, and surgeons that will improve quality of life. 

More awareness, inquiry, and recognition from the providers of health is important to improve patient outcomes. If the field continues to improve, we may find better treatment options available for, or a cure for adiposis dolorosa in the future.

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• National Organization for Rare Disorders (NORD). (2022). Dercum’s disease. 
• Herbst, K. L. (2012). Rare adipose disorders (RADs) masquerading as obesity. Acta Pharmacologica Sinica, 33(2), 155–172. 
• Child, A. H., Gordon, K. D., Sharpe, P., Brice, G., Ostergaard, P., Jeffery, S., … & Mortimer, P. S. (2010). Lipedema: An inherited condition. American Journal of Medical Genetics Part A, 152A(4), 970–976. 
• Herbst, K. L., & Asare-Bediako, B. (2021). Dercum’s disease and associated conditions: An overview. Lymphatic Research and Biology, 19(6), 598–605.