Panniculitis is a progressive lesion of subcutaneous fat of an inflammatory nature, leading to the destruction of fat cells and their replacement by connective tissue with the formation of nodes, plaques or infiltrates. In the visceral form of panniculitis, fatty cells of the liver, pancreas, kidneys, fatty tissue of the omentum or retroperitoneal region are affected. Diagnosis of the disease is based on the clinic and histological examination data. Treatment depends on its form.
Approximately half of the cases occur in a spontaneous (idiopathic) form of the disease, which is more common in women aged 20 to 50 years. The remaining 50% are cases of secondary panniculitis, developing against the background of systemic and skin diseases, immunological disorders, the effects of various provoking factors (cold, some medications). It is known that the basis of the development of panniculitis is a violation of the peroxidation of fats. But, despite numerous studies in the field of etiology and pathogenesis of this disease, dermatology still does not have a clear idea of the mechanism of its occurrence.
In the classification of panniculitis, there are primary or spontaneous forms of the disease (Weber-Christian) and secondary. Secondary form includes:
- immunological — often observed against the background of systemic vasculitis, in children there may be a variant of the course of nodular erythema;
- lupus (lupus-panniculitis) — develops with a deep form of systemic lupus erythematosus, characterized by a combination of symptoms of panniculitis with skin manifestations typical of discoid lupus;
- enzymatic — is associated with the effect of pancreatic enzymes, the level of which in the blood increases with pancreatitis;
- proliferative-cellular — occurs with leukemia, lymphoma, histiocytosis, etc.
- cold — a local form of panniculitis that develops in response to severe cold exposure, manifested by dense pink nodes that pass within 2-3 weeks;
- steroid — may occur in children within 1-2 weeks after the end of general treatment with corticosteroids, characterized by spontaneous healing and does not require therapy;
- artificial — associated with the introduction of certain medications;
- crystalline — develops with gout and renal insufficiency due to the deposition of urates and calcifications in the subcutaneous tissue, as well as with the deposition of crystals after injections of pentazocine or meneridine;
- panniculitis associated with a deficiency of α1-antitrypsin (an α-protease inhibitor) is a hereditary disease accompanied by systemic manifestations: vasculitis, hemorrhages, pancreatitis, hepatitis, nephritis.
According to the shape of the nodes formed with disease, nodular, infiltrative and plaque variants of the disease are distinguished.
The main manifestation of spontaneous panniculitis is nodular formations located in subcutaneous fat at various depths. Most often they appear on the legs and arms, less often — in the abdomen, chest or face. After the resolution of the nodes of panniculitis, foci of fatty tissue atrophy remain, which look like rounded areas of skin sinking.
The nodular variant is characterized by the appearance in the subcutaneous tissue of typical separately located nodes ranging in size from 3-4 mm to 5 cm. The skin above the nodes can have a color from normal to bright pink.
The plaque variant is a separate cluster of nodes that coalesce to form lumpy conglomerates. The skin color above such formations can be pink, bard or bard-blue. In some cases, conglomerates of nodes spread to the entire fiber of the lower leg, shoulder or thigh, while squeezing vascular and nerve bundles, which causes severe pain and swelling of the limb, leading to lymphostasis.
The infiltrative variant of panniculitis proceeds with the melting of nodes or their conglomerates. At the same time, in the area of the node or plaque, as a rule, a bright red or bard shade, there is a fluctuation typical of an abscess or phlegmon. However, when the nodes are opened, not pus comes out of them, but an oily yellow mass. In place of the opened node, a long-term non-healing ulceration is formed.
A mixed variant of panniculitis is rare and represents a transition of the nodular form into a plaque, and then into an infiltrative one.
Changes in subcutaneous fat in the case of spontaneous panniculitis may not be accompanied by a violation of the general condition of the patient. But more often at the beginning of the disease there are symptoms similar to the manifestations of acute infections (ARI, influenza, measles, rubella, etc.): headache, general weakness, fever, arthralgia, muscle pain, nausea.
The visceral form of panniculitis is characterized by a systemic lesion of fat cells throughout the body with the development of pancreatitis, hepatitis, nephritis, the formation of characteristic nodes in the retroperitoneal tissue and omentum.
According to its course, panniculitis can be acute, subacute and recurrent, lasting from 2-3 weeks to several years. The acute form of panniculitis is characterized by a marked change in the general condition with high fever, myalgia, joint pain, impaired kidney and liver function. Despite the ongoing treatment, the patient’s condition progressively worsens, occasionally there are short remissions, but within a year the disease ends in a fatal outcome.
The subacute course of panniculitis is more smoothed. It is typical for him to have a violation of the general condition, fever, changes in liver function tests, resistance to treatment. The most favorable is the recurrent or chronic course of panniculitis. At the same time, relapses of the disease are not difficult, often without changing the general state of health and alternate with long-term remissions.
Diagnosis of panniculitis is carried out by a dermatologist together with a rheumatologist, a nephrologist and a gastroenterologist. The patient is prescribed a biochemical analysis of blood and urine, liver tests, a study of pancreatic enzymes, a Rehberg test. The detection of visceral panniculitis nodes is carried out using ultrasound of the abdominal cavity, ultrasound of the kidneys. pancreas and liver ultrasound. Sowing blood for sterility allows you to exclude the septic nature of the disease. To differentiate the infiltrative variant of panniculitis from the abscess, a bacteriological examination of the separated opened node is carried out.
The exact diagnosis of panniculitis is established by the results of a node biopsy. Histological examination reveals inflammatory infiltration, necrosis of fat cells and their replacement by connective tissue. Diagnosis of lupus panniculitis is based on data from immunological studies: determination of antinuclear factor, antibodies to ds-DNA, complement C3 and C4, antibodies to SS-A, etc.
Therapy of panniculitis is carried out comprehensively, depending on its form and course. For the treatment of nodular form with a chronic course, nonsteroidal anti-inflammatory drugs (naproxen, diclofenac) and antioxidants (vitamin E, ascorbic acid) are prescribed, single nodular formations are pricked with glucocorticoids. Physiotherapy is effective: UHF, hydrocortisone phonophoresis, magnetotherapy, ozokerite, ultrasound, laser therapy.
In the plaque and infiltrative form, the subacute course of panniculitis, glucocorticosteroids (hydrocortisone, prednisone) and cytostatics (cyclophosphane, methotrexate) are used. To improve liver function, it is advisable to prescribe hepatoprotectors. Treatment of secondary forms of panniculitis necessarily includes therapy of a background disease: pancreatitis, SLE, vasculitis, gout.