Diagnosis of nodular polyarteritis

Diagnosis of nodular polyarteritis is often difficult, which is associated with nonspecificity of initial symptoms, polymorphism of clinical manifestations, the absence of specific laboratory markers. The basis of the diagnosis is primarily a clinical picture, which becomes apparent during the first 3 months of the disease. When establishing the diagnosis, specific clinical syndromes (the main diagnostic criteria) are taken into account. Ancillary significance are signs such as an increase in body temperature, weight loss, joint and muscle pain, leukocytosis, an increase in ESR, markers of viral hepatitis B.

The classification criteria for nodular polyarteritis in children (hereinafter the criteria are based on specificity and sensitivity from the highest to lowest percent)

Criteria	Refinement
Basic
Multiple asymmetric mononews or asymmetric polyneuritis	Combined or sequential lesion of the radial, ulnar, median, peroneal and other nerves
Ischemic bowel disease	Infarction, bowel wall necrosis with single or multiple lesions
Syndrome of arterial hypertension	A persistent increase in diastolic pressure in combination with urinary syndrome and, possibly, hepatitis B markers
Characteristic angiographic changes	Aneurysms of small and medium intraorganic arteries in combination with focal vascular deformity (liver, kidney and other arteries)
Necrotizing vasculitis (according to biopsy data)	Destructive-proliferative vasculitis of small and middle arteries of muscle type, revealed during biopsy
Auxiliary
Pain in the joints and / or muscles	Persistent pain, causalgia of large joints and distal limb muscles
Fever	Increase in body temperature above 38 ° C daily or episodic with profuse sweats for 2 weeks or more
Peripheral blood leukocytosis	Leukocytosis more than 20,0х109 / l, determined in three consecutive analyzes
Weight Loss	Decreased body weight of more than 15% of the initial in a short period, not associated with starvation

The diagnosis of nodular polyarteritis is established in the presence of at least two basic or one basic and three auxiliary criteria.

[1], [2], [3], [4], [5],

Laboratory diagnosis of nodular polyarteritis

In the active period of nodular polyarteritis in a general blood test, moderate normochromic anemia, neutrophilic leukocytosis, increased ESR are determined.

In the general analysis of urine, transient changes in the precipitate can be detected.

Biochemical blood analysis has applied value, revealing the changes of some indicators, in particular, transferase activity and nitrogenous slags.

When immunological study in the active period in all patients determine the increase in the concentration of C-reactive protein, it is possible to detect a moderate increase in IgA, IgG, positive rheumatoid factor.

The system of blood clotting with nodular polyarteritis is characterized by a tendency to hypercoagulable, so the determination of the state of hemostasis should be the initial and subsequent for monitoring the sufficiency of therapy. Hypercoagulation is most pronounced with juvenile polyarteritis.

In patients with classical nodular polyarteritis, HBsAg and other hepatitis B markers are detected (without clinico-laboratory and epidemiological signs of the disease).

Instrumental diagnosis of nodular polyarteritis

According to the indications prescribe ECG, Echocardiography, chest X-ray, ultrasound of the abdominal cavity organs, angiography, biopsy.

On the ECG, you can identify signs of metabolic disturbances in the myocardium, tachycardia. In the presence of myocarditis, conduction, extrasystole, and decreased electrical activity of the myocardium can be detected. When coronary arteries are affected, ischemic changes in the heart muscle are detected.

In echocardioma, in the case of myocarditis, enlargement of the heart cavities, thickening and / or hyperechoogenicity of the walls and / or papillary muscles, reduction of the contractile and pumping functions of the myocardium, in the presence of pericarditis - lamination or thickening of the pericardium leaves.

With ultrasound of the abdominal organs and kidneys, nonspecific changes are noted more often in the form of strengthening of the vascular pattern and / or echogenicity of the parenchyma.

On the roentgenogram of the chest in the active period of the disease, there is an increase in the vascular pattern, sometimes a change in pulmonary interstitium.

Aortography is prescribed for nodular polyarteritis, which proceeds with arterial hypertension, with a diagnostic and differential-diagnostic purpose. Aneurysms of the middle and small vessels of the kidneys, liver, spleen and defects of the contrasting parenchyma of the affected organs can be detected on angiograms, which serves as an angiographic criterion of the disease.

A biopsy of the skin, subcutaneous tissue and muscles, rarely - the kidneys, is carried out in doubtful cases. A biopsy is desirable before the basal therapy. Morphological sign confirming the diagnosis of nodular polyarteritis is a destructive-productive vasculitis that can be detected only if a biopsy is carried out from a skin site with a nodule, a liver or near a necrosis.

Classification criteria for juvenile polyarteritis

Criteria	Refinement
Basic
Gangrene Fingers and / or Skin Necrosis	Acute development of dry asymmetric gangrene with involvement of I-III fingers, mummification of skin areas
Nodular eruptions	Intradermal or subcutaneous nodules up to 1 cm in diameter along the vessels
Infarction of the tongue	Painful wedge cyanosis of the tongue with the development of necrosis
Livedo tree	Cyanotic coarse-wool net on the distal parts of the extremities, intensifying in the cold and standing position
Auxiliary
Necrotizing vasculitis (according to biopsy data)	Destructive-proliferative vasculitis of small and medium-sized arteries of muscle type, revealed during biopsy
Weight Loss	Decreased body weight of more than 15% of the initial in a short period, not associated with starvation
Pain in the joints and / or muscles	Persistent pain, causalgia of large joints and distal limb muscles
Fever	Increase in body temperature above 38 C daily or episodic with profuse sweats for 2 weeks or more
Peripheral blood leukocytosis	Leukocytosis is more than 20.0 × 10 9 / L, defined in three consecutive analyzes

The diagnosis of juvenile polyarteritis is established with at least three basic or two main and three auxiliary criteria.

[6], [7], [8], [9], [10], [11], [12]

Differential diagnosis of nodular polyarteritis

With acute onset of juvenile polyarteritis with high body temperature, joint and muscle pains, skin rashes, hepatomegaly, there is often a need for differential diagnosis with sepsis, juvenile rheumatoid arthritis, juvenile dermatomyositis, systemic lupus erythematosus, Kawasaki syndrome, nonspecific aortoarteriitis.

In carrying out differential diagnostics, one should imagine that destructive arthritis is not characteristic for nodular polyarteritis, as opposed to juvenile dermatomyositis, juvenile dermatomyositis is less pronounced in juvenile polyarteritis than in juvenile rheumatoid arthritis, and the syndrome of muscular weakness is not so pronounced, the liver and skin necrosis is located mainly on the distal parts of the limbs, do not observe periorbital lilac erythema . In contrast to systemic lupus erythematosus, in patients with juvenile polyarteritis more often there is a tree-like, rather than a reticular lyvedo, distal gangrene, hyperleukocytosis. For nodular polyarteritis are not characterized by endocarditis, polyserositis and nephrotic syndrome, with it do not define LE-cells.

Differential diagnosis of nodular polyarteritis is difficult when a child suddenly develops high blood pressure. In such cases, the diagnosis of nodular polyarteritis should often be established by elimination, consistently rejecting the assumption of pheochromocytoma, stenosis of the renal arteries, pyelonephritis with outcome in nephrosclerosis, chronic glomerulonephritis. In favor of nodular polyarteritis testifies: a persistent high level of arterial pressure, combined with signs of systemic vascular lesions, fever, increased ESR and leukocytosis, HBs-antigenemia (without a hepatitis clinic).

[13], [14], [15]