Lipedema: symptoms and causes

What is lipedema?

Fat legs, prominent buttocks – lipedema is often incorrectly classified as being overweight or obesity. Lipedema has nothing to do with being overweight. Lipedema is the result of a disordered accumulation of fat cells in the extremities. Often only the legs are affected, frequently however both the arms and legs.

The exact cause and development of lipedema have not yet been conclusively researched. Currently under discussion are a familial predisposition, disruption of lipid metabolism and hormonal factors. Lipedema affects women nearly exclusively and typically begins in phases of hormonal changes, such as puberty or pregnancy.

The initial description by Edgar V. Allen und Edgar A. Hines 1940 (Allen and Hines 1940) lists the following characteristics:

• Lipedema affects nearly exclusively women.
• The main symptom is a fatty swelling of the legs existing for some years and in some cases already detected in girlhood.
• Lipedema generally does not affect the feet.
• The enlargement of the limbs is symmetrical.
• The disorder is usually associated with weight gain.
• Swelling below the knee appears more often when the patient is often on their feet and in warm weather.
• Pain in the legs belongs to the everyday.
• In many cases there is a history of a similar state in other family members.

Lipedema is symmetrical, in contrast to lymphedema. The accumulation of lipid tissue is distributed evenly on the legs and/or arms. The hands and feet are typically not affected by lipedema. A collar or sleeve often forms at the joints.

In lipedema, affected patients suffer not only physically from contact sensitivity or pressure pain, but also mentally regarding their appearance. 

Overweight and obesity are the most common disorders existing concurrently with lipedema. Sie  verschlechtern die Symptome des Lipödems und begünstigen das Voranschreiten der Erkrankung. The body mass index (BMI) used to characterise the level of obesity is of little significance in patients with lipedema as the index leads to falsely high values in the range of overweight or mild obesity owing to the accumulation of fatty tissues.

According to Herpetz, lipedema is subdivided into seven types depending on the affected region (thigh, calf, whole leg, lower leg, upper arm, whole arm, lower arm). There further exists a frequently used staging classification 1-4, often incorrectly equated with the severity of the lipedema (see figures). Dies sollte eigentlich nicht erfolgen, da die Schmerzhaftigkeit des Gewebes – und damit der Leidensdruck der Patientinnen  und Patienten– nicht zwingend mit der Volumenvermehrung übereinstimmt.  

Causes of lipedema

The exact causes of lipedema are not yet known. As it affects nearly exclusively women, hormonal factors appear to have a decisive impact. This is supported by the appearance of the disease during puberty, after a pregnancy or around menopause. The increased susceptibility of women could also be associated with the structure of fatty tissue in females, which differs to that in males. Interestingly, weight gain often leads to aggravation of the disease. It is also assumed that a certain predisposition for the onset of the disease is responsible and that lipedema is thus hereditary.

Lipedema-like changes also occur in men in isolated cases. In this event, another disease is usually present, which influences the hormonal balance (e.g. testosterone deficiency owing to liver damage, hormonal disorders or hormone-active therapies).

Recognise lipedema

Unfortunately there is no "one" laboratory value that allows diagnosis of lipedema. Ultimately there is a list of criteria that lead to diagnosis. The following points are suggestive for lipedema:

• Beidseitige symmetrische und schmerzhafte Fettgewebsvermehrung an Armen und/ oder Beinen, ohne Beteiligung von Händen und Füssen (Kragenbildung an den Gelenken)
• Disproportion zwischen Rumpf und Extremitäten
• Schwellung und Schweregefühl in den betroffenen Gliedmassen
• Berührungs-, Spontan- und/ oder  Druckschmerz im betroffenen Gewebe
• Starke Neigung zu Hämatombildung (Bluterguss)
• Oftmals dellige oder knotige Struktur der Haut und des Unterhautgewebes
• Familiäre Vorbelastung

Especially important is the demarcation of the lipedema from a lipohypertrophy, usually triggered by obesity. This also leads to a symmetrical accumulation of fatty tissues in the arms and legs. Usually however, there is no disproportion compared with the trunk and typically there is also no pain, which is characteristic for lipedema.

Diagnosis and stages

When considering a diagnosis of lipedema, the affected person is first examined and palpated. It is important to determine whether this concerns lipedema or lymphedema. Lipedema is generally recognised by the typical distribution pattern and painfulness of the fat pads.

Even if the name "edema" suggests so, lipedema is not concurrent per se with swelling of the tissues, which is rather caused by fluid retention as in lymphedema. When the tissue is pressed, there is no resultant indentation as in lymphedema. The "Stemmer sign" is also negative in lipedema. This means that a skin fold at the base of the second toe or at the base of the middle finger can be pinched and raised (lipedema pinch test).

Possible mixed forms should also be considered for a correct diagnosis.

Lipedema in the legs is then differentiated according to the following 4 stages of severity:

Stadium 1: Hautoberfläche glatt, Unterhautfettgewebe verdickt und weich ohne Knoten. Incipient collar formation at the joints.

Stadium 2: Hautoberfläche uneben und häufig wellenartig, Unterhaut verdickt und knotenartigen Strukturen.

Stadium 3: Ausgeprägte Umfangsvermehrung, Hautoberfläche sehr uneben, Unterhaut verdickt und verhärtet, grosse Fettwülste unter der Haut und überhängende Gewebeanteile, Gehen unter Umständen behindert.

Stadium 4: Als viertes Stadium wird häufig das Lipo-Lymphödem (Lipödem mit sekundärem Lymphödem) aufgeführt.

Mixed forms of lipedema: lipedema with secondary lymphedema

There are often mixed forms in which the lipedema may appear together with lymphedema or phlebedema (edema associated with a venous disorder). The lymphedema or phlebedema may also appear at any stage of lipedema. 

For these mixed forms, lymphedema therapy or treatment of the venous disorder should take place in addition to the lipedema therapy.