Necrobiosis lipoidica
Encyclopedia
Necrobiosis lipoidica is a necrotising
skin condition that usually occurs in patients with diabetes but can also be associated with Rheumatoid Arthritis. In the former case it may be called necrobiosis lipoidica diabeticorum (NLD). NLD occurs in approximately 0.3% of the diabetic population, with the majority of sufferers being women (approximately 3:1 females to males affected).
Necrobiosis lipoidica commonly occurs simultaneously with granuloma annulare
and with sarcoidosis
. The severity or control of diabetes in an individual does not affect who will or will not get NLD. Better maintenance of diabetes after being diagnosed with NLD will not change how quickly the NLD will resolve.
but may become tender and ulcerate when injured. The first symptom of NL is often a "bruised" appearance (erythema) that is not necessarily associated with a known injury. The extent to which NL is inherited is unknown.
NLD appears as a hardened, raised area of the skin. The center of the infected area usually has a yellowish tint while the area surrounding it is a dark pink. It is possible for the infected area to spread or turn into an open sore. When this happens the patient is at greater risk of developing ulcers. If an injury to the skin occurs on the affected area, it may not heal properly or it will leave a dark scar.
degeneration, combined with a granulomatous
response. It always involves the dermis
diffusely, and sometimes also involves the deeper fat layer. Commonly, dermal blood vessels are thickened (microangiopathy).
It can be precipitated by local trauma, though it often occurs without any injury.
There is no clearly defined cure for necrobiosis. Although there are some techniques that can be used to diminish the signs of necrobiosis such as a steroid cream or injection into the affected area, this process may be effective for only a small amount of those treated. Steroid cream has been known to cause thinning of the skin, so if used, it is best to wrap the area with some form of plastic wrap or cloth. Even then, this process can take long periods of time.
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
skin condition that usually occurs in patients with diabetes but can also be associated with Rheumatoid Arthritis. In the former case it may be called necrobiosis lipoidica diabeticorum (NLD). NLD occurs in approximately 0.3% of the diabetic population, with the majority of sufferers being women (approximately 3:1 females to males affected).
Necrobiosis lipoidica commonly occurs simultaneously with granuloma annulare
Granuloma annulare
Granuloma annulare is a chronic skin disease consisting of a rash with reddish bumps arranged in a circle or ring. Granuloma annulare is different from warts, and cryotherapy treatment will not work...
and with sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
. The severity or control of diabetes in an individual does not affect who will or will not get NLD. Better maintenance of diabetes after being diagnosed with NLD will not change how quickly the NLD will resolve.
Clinical appearance
NL/NLD most frequently appears on the patient's shins, often on both legs, although it may also occur on forearms, hands, trunk, and, rarely, nipple, penis, and surgical sites. The lesions are often asymptomaticAsymptomatic
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical...
but may become tender and ulcerate when injured. The first symptom of NL is often a "bruised" appearance (erythema) that is not necessarily associated with a known injury. The extent to which NL is inherited is unknown.
NLD appears as a hardened, raised area of the skin. The center of the infected area usually has a yellowish tint while the area surrounding it is a dark pink. It is possible for the infected area to spread or turn into an open sore. When this happens the patient is at greater risk of developing ulcers. If an injury to the skin occurs on the affected area, it may not heal properly or it will leave a dark scar.
Pathophysiology
Although the exact cause of this condition is not known, it is an inflammatory disorder characterised by collagenCollagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
degeneration, combined with a granulomatous
Granuloma
Granuloma is a medical term for a tiny collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances that it perceives as foreign but is unable to eliminate. Such substances include infectious organisms such as bacteria and fungi as well as...
response. It always involves the dermis
Dermis
The dermis is a layer of skin between the epidermis and subcutaneous tissues, and is composed of two layers, the papillary and reticular dermis...
diffusely, and sometimes also involves the deeper fat layer. Commonly, dermal blood vessels are thickened (microangiopathy).
It can be precipitated by local trauma, though it often occurs without any injury.
Diagnosis
NL is diagnosed by a skin biopsy, demonstrating superficial and deep perivascular and interstitial mixed inflammatory cell infiltrate (including lymphocytes, plasma cells, mononucleated and multinucleated histiocytes, and eosinophils) in the dermis and subcutis, as well as necrotising vasculitis with adjacent necrobiosis and necrosis of adnexal structures. Areas of necrobiosis are often more extensive and less well defined than in granuloma annulare. Presence of lipid in necrobiotic areas may be demonstrated by Sudan stains. Cholesterol clefts, fibrin, and mucin may also be present in areas of necrobiosis. Depending on the severity of the necrobiosis, certain cell types may be more predominant. When a lesion is in its early stages, neutrophils may be present, whereas in later stages of development lymphocytes and histiocytes may be more predominant.There is no clearly defined cure for necrobiosis. Although there are some techniques that can be used to diminish the signs of necrobiosis such as a steroid cream or injection into the affected area, this process may be effective for only a small amount of those treated. Steroid cream has been known to cause thinning of the skin, so if used, it is best to wrap the area with some form of plastic wrap or cloth. Even then, this process can take long periods of time.