What is Lipoatrophy?
Lipoatrophy, also called lipodystrophy, is a condition which describes a loss of fat tissue in a localized area. Lipoatrophy, which usually occurs following frequent subcutaneous injections, is not a disease itself, but is a result of other conditions which lead to a loss of fat tissue in an area.
Lipoatrophy in the Right Arm
Lipoatrophy or lipodystophy can be partial, localized, or total.
Localized lipodystrophy is a localized adipose tissue loss which involves one or more areas. This is the most common form of lipodystophy seen in patients who receive multiple subcutaneous injections.
Partial lipodystropy is a symmetrical loss of fat tissue in the face with similar occurrence on the trunk and arms. Partial lipodystophy is correlated with diabetes, renal disease, immunologic disorders, and hyperlipidemia.
Partial Lipoatrophy on the Face
Total lipodystrophy, which may be acquired or congenital, involves complete loss of adipose tissue. Causes include insulin resistance, hyperglycemia, hypermetabolism, and hyperlipidemia.
Localized lipodystophy involves single or multifocal, atrophic, well-demarcated lesions. Localized lipoatrophy is rare; its occurrence without frequent administration of subcutaneous injections is usually rarer. Lipoatrophy is benign and does not result in cancer. There is a low morbidity and mortality rate, and the severity is associated with the involved organ and the occurrence of comorbid conditions. Lipoatrophy is not associated with specific races, and females are more prone to develop it due to fewer muscles beneath the subcutaneous layer. Depending on the presence of causative factors, it can occur at any age. The main concern for lipodystrophy is its cosmetic implication as the appearance of fat loss may be disturbing and can affect the body image of patients.
Most commonly, lipoatrophy may increase in size and may disappear. There are no surface skin changes that happen from the fat loss, but some may experience hyperpigmentation on the skin.
Symptoms of Lipoatrophy
Lipoatrophy manifests as:
- Presence of depression in the skin in different area.
- Single or multifocal depression in the skin
- Well-demarcated and atrophic characteristics
- Non-pigmented or pigmented lesions
- Absence of pain
- Loss of fat in proximal areas of the body (ex., thighs, buttocks, and upper arms)
- fat loss in face, breasts, scalp, and distal areas of the body (less frequent)
Causes of Lipoatrophy
The exact cause of most lipoatrophy cases is unknown. Local lipoatrophy is usually a result of intradermal and subcutaneous injections. Due to a recurrent trauma to one area of the body as a result of injection, the macrophages release cytokines which lead to increased catabolism or breakdown of adipose tissues. These cytokines include interleukin-1, tumor necrosis factor, histamine, bradykinins, and prostaglandins. Specific medications that lead to lipoatrophy include:
- Insulin injections
Patients with diabetes who need daily insulin injections are at risk of lipoatrophy. Animal insulin may also lead to lipoatrophy due to its reaction with the fat cells in the body, although this case is very rare.
- Human growth hormone injections
People with growth hormone deficiency require the administration of growth hormone every day or every week, depending on the physician’s prescription. One study reported the occurrence of lipoatrophy in 13 patients with 3 patients developing it after the first injection.
Heparin is also injected subcutaneously and may result in lipoatrophy. Heparin also causes hematoma formation when incorrect injection technique is employed.
- Other synthetic hormones
Other hormones such as erythropoietin are also required to be injected in scheduled doses. The frequent administration of these may lead to localized lipoatrophy.
- Glatiramer acetate (copaxone)
This drug is used to treat multiple sclerosis. When given subcutaneously, it may lead to lipopatrophy.
Corticosteroids are also given parenterally, specifically, the intramuscular route. Injections are more common for patients with severe pain and inflammation who do not respond to oral treatments of anti-inflammatory drugs.
- Iron Dextran
This is an iron preparation administered through the intramuscular route. This may also lead to skin irritation.
- IM antibiotics
Antibiotics such as penicillins are also injected intramuscularly.
Vaccines in the form of diphtheria, pertussis, and tetanus cause reactions in the injection site, which may possibly lead to lipoatrophy.
Other medication causes of lipoatrophy include HIV lipoatrophy. Lipoatrophy is a common complication of protease inhibitor administration in HIV patients. These are antiretroviral medications that may lead to central fat accumulation and fat tissue loss in other parts of the body. Lipoatrophy caused by HIV medications are usually generalized or total.
Diseases that cause lipoatrophy include:
- Sjögren syndrome
- Pyogenic infections
- Systemic lupus erythematosus
- Connective tissue disorders
Lipoatrophy is diagnosed mainly by the physical symptoms and physical examinations. Inflammatory lipoatrophies can be detected by the use of serologic markers to determine any connective tissue disease. Histologic examinations, the trademark diagnostic test for lipopatrophy, may be done to determine any cellular changes and will guide the treatment modalities to be employed. Most often, lipoatrophies are benign conditions. Histologic examinations reveal the presence of lobules of small fat cells embedded in connective tissues. This occurrence is termed as involutional fat. There is also the presence of myxoid stroma, peripheral lobular accentuation, and absence of inflammatory cells.
Treatment of Lipoatrophy
Treatment for lipoatrophy is primarily focused on surgery. There are no medications, diet, and activity that will correct the problem. Fat loss under the skin will not be replaced with certain medical treatments.
Surgery is the treatment of choice for lipoatophy. Patients who are very conscious about their appearance, especially when the lipoatrophy occurs on the face, would opt for surgical treatment to regain aesthetic confidence. Lipoatrophy when left untreated with surgery may not cause other complications. Aesthetic reasons are the primary considerations for surgery.
The surgical procedure employed is the placement of adipofascial flaps under the skin to even out the integumentary system and correct skin depressions.
Lipoatrophy Surgery involving Placement of Flaps
Management for lipoatrophy caused by insulin injections require the shift from animal insulin to purified human insulin.
Prevention of Lipoatrophy
Localized lipoatrophy is primarily prevented by rotation of injection sites. Everyday injections should be administered in different parts of the body to minimize overuse of a certain spot which may cause lipoatrophy. Other conditions leading to lipoatrophy should also be managed to prevent the loss of fat tissue.
Prognosis of Lipoatrophy
Patients with lipoatrophy have a normal life expectancy and will not experience other complications aside from cosmetic affectation. Lipoatrophy is usually benign.