OVERVIEW
Disseminated eosinophilic collagen disease is an allergic disease characterized by fever, respiratory symptoms, hepatosplenomegaly, and peripheral blood eosinophilia. The age of onset ranges from 6 months to 47 years, with a male-to-female ratio of 13:10.
Etiology
The exact cause of the disease is unknown. Because of eosinophilia, asthma, and elevated serum immunoglobulin E (IgE), it may be a type I hypersensitivity-mediated disease due to some cause.
Symptoms
The main manifestations are malaise, generalized aching and discomfort, poor appetite, irritability and insomnia. The disease, like other collagen diseases, is characterized by multi-system damage.
1. Fever
Almost all cases have fever, and it is mostly parallel to the activity of the disease, which can be flaccid or auditory fever, and the temperature is mostly above 38℃.
2. Joint symptoms
It is characterized by polyarthritis or arthralgia, sometimes with joint effusion and joint swelling. Joint symptoms may be mild or severe, and in severe cases, activities are limited and morning stiffness occurs, but most of them do not cause joint deformation. The joints of the whole body can be involved, with the joints of the limbs more common, especially the joints of the hands are most likely to be involved. Some cases are accompanied by muscle pain and muscle weakness.
3. Skin lesions
There are several types of skin changes: erythema, erythema multiforme; papules; dermatitis, plaques, yellow tumor-like damage; necrosis, scarring; erythroderma.
One type of rash can exist alone, or several types can coexist or appear successively, in which the forehead and trunk cornified papules are the most common skin changes in the early stage, with the development of the disease, it can gradually spread to the limbs, and transformed into urticaria-like erythema, rheumatism, or atopic dermatitis-like rashes, accompanied by a feeling of intense itching. The beginning of the appearance of millet papules can also be quickly transformed into the whole body skin redness, thickening and flaking, mostly accompanied by severe itching, that is, the so-called erythroderma-like rash. Sometimes it may be accompanied by mossy lesions on the extremities, with fine reticular pigmentation remaining after the lesions subside. The lesions can also start as scattered erythema with clear edges all over the body, ranging in size from an egg to the palm of the hand, with bright red edges and a lighter color in the center, which is slightly elevated above the skin. The erythema is interspersed with light brown pigmentation, often fused with each other to form plaques or yellow tumor-like changes. When erythema is severe, localized necrosis may occur, leaving a scar after fading. Different types of lesions may appear in different parts of the body, such as the trunk is often manifested as erythema, polymorphic exudative erythema-like damage, while the limbs are manifested as corn-like papules or atopic dermatitis-like rash. In short, the disease has a diversity of skin changes, but its constant feature is dissemination, mostly accompanied by itching.
4. Cardiopulmonary symptoms
In the active phase of the lesion attack, most patients have respiratory symptoms, manifested as different degrees of cough, sometimes asthma-like dyspnea, coughing foamy sputum or mucus sputum, eosinophilia in sputum smear. Due to eosinophilic infiltration of lung tissue, it can cause transient pneumonia. As long-term application of glucocorticoid treatment can make the body resistance decline, it is very easy to secondary bacterial infection, and finally lead to bronchopneumonia, which aggravates the condition or even death.
More than half of the patients have heart enlargement, but the early stage is mostly asymptomatic, and congestive heart failure can occur in the later stage. Sinus tachycardia is present in almost all cases. The heart rate is separated from the body temperature.
5. Gastrointestinal symptoms
Abdominal pain, nausea, vomiting, occasional diarrhea or constipation, or alternating between the two, which may be caused by eosinophilic infiltration of the gastrointestinal tract. More than half of the patients have liver and spleen enlargement.
6. Neurological symptoms
Neurological symptoms may be present in some cases, which may be characterized by gait disorder, consciousness disorder, visual impairment, limb flaccid paralysis, eyelid ptosis, intracranial hypertension sign and pathological reflexes.
7. Other
About 1/3 of the patients have enlarged lymph nodes, which may be generalized or localized, especially in the neck and axilla.
Examination
1. Blood count and sedimentation
The total number of leukocytes may be increased, but only eosinophils are elevated in the categorized count, and most of them are of mature type. Most of them are of mature type. In the active stage, the blood sedimentation rate is often increased.
2. Urine routine
There may be mild proteinuria, microscopic hematuria or tubular urine, but the urine changes are usually mild.
3. Biochemical examination
Liver function may be mildly abnormal, and protein electrophoresis may show elevated gamma globulin.
4. Immunologic examination
All cases have elevated IgE, immunoglobulin G (IgG), 2/3 of the patients are positive for rheumatoid factor, about 1/5 of the patients are positive for antinuclear antibody, and the cellular immunity tests such as E-rosette number and phytohaemagglutinin (PHA) markers are low, and complement is low.
5. Chest X-ray examination
There are different degrees of inflammatory infiltration, and sometimes the heart is enlarged. Individual cases may have hand deformity, narrowing of joint cavity, bone destruction, and occasionally joint dislocation or subluxation.
Diagnosis
Diagnosis can be made on the basis of skin lesions, clinical manifestations, pathologic features and eosinophilia in peripheral blood, combined with the features of multi-system involvement.
Differential diagnosis
The following diseases with eosinophilia should be excluded:
1. Nodular polyarteritis
The main cause is visceral damage, especially cardiac, renal and neurological symptoms. The skin lesions are mainly purple spots or nodules distributed along the arterial direction, and there is no diffuse itchy granular papules or plaques. Pathologic changes are dominated by fibrolytic necrotizing middle and small arteritis, mostly without epidermal and dermal collagen fiber changes. Rheumatoid factor and antinuclear antibodies are negative. These pathologic and laboratory abnormalities are different from disseminated eosinophilic collagen disease.
2. Allergic granuloma
It is a granulomatous vasculitis with multiorgan involvement, characterized by pulmonary infiltration, episodic asthma, and eosinophilia in the peripheral blood. The lesions are mainly cutaneous or subcutaneous nodules and purple spots. Pathologic changes were fibrin-like necrotizing vasculitis, mainly involving muscular arteries, with granulomatous changes. There is no skin collagen fiber changes, rheumatoid factor, anti-nuclear antibody are negative.
3. Wegener’s granuloma
It is a kind of necrotizing granulomatous vasculitis. It mainly involves the respiratory tract, kidneys and eyes, often with bone destruction in the upper respiratory tract. There are no pruritic granulomatous papules and plaques, and no collagen fiber changes in the skin. Antinuclear antibodies are negative and IgE levels are normal.
Treatment
Control of recurrent attacks with immunosuppressants or glucocorticoids. If long-term application of hormones is required due to prolonged lesions, small-dose alternate-day therapy is appropriate. If the pulmonary symptoms worsen with persistent high fever in the course of medication, it is suggestive of secondary infection in the lungs, and the infection should be controlled with a sufficient amount of effective antibiotics.
Prognosis
Better, but often recurrent, can die of secondary infection of the lungs.