Henoch-Schoenlein purpuraD69.0

Mostly acute, frequently infection-associated, leukocytoclastic IgA1-positive immune complex (multi-organ) vasculitis (small vessel vasculitis), which occurs mainly in small children and adolescents and is clinically characterized dermatologically by a (palpable) purpura. The disease is the most common syndromal vasculitis in children.

Incidence: 10-15/100.000 children/year.

Often associated with streptococcal infections of the upper respiratory tract. Preferred occurrence during the cold season. Other infections, e.g. viral infections or vaccinations against viral diseases (meningitis C) are also blamed as triggers, even if the connections are not always clear.

In rare cases, the disease in adults can also be induced by alcohol.

A monclonal (MGUS) or polyclonal IGA gammopathy must be clarified(Umemura H et al.).

Occurring mainly (about 75%) in children between the ages of 4 and 11, no gender preference. No preference for ethnic groups.

Rare occurrence also in adults (into old age). IgA-associated leukocytoclastic vasculitis tends to be severe and regular in adults, with systemic involvement; systemic manifestations (severe illness, arthritides, renal pain) may dominate the clinical picture. IgG- or IgM-associated vasculitides are more common in adults (note: a clear classification of the deposited immunoglobins is not always possible).

The disease occurs seasonally more frequently in the winter months.

Symmetrical infestation; mainly on the extensor sides of the legs (the lower legs are preferred in stasis) and on the buttocks.

The clinical picture corresponds to an acute or chronic inflammatory systemic disease with varying organ involvement. At the beginning, during a prodromal phase lasting 14-21 days, vague general symptoms often develop with fever, uncharacteristic rheumatic complaints with arthralgias, arthritides and myalgias. Less commonly, myositis is present.

Skin: The characteristic clinical dermatologic picture (leading symptom) is characterized by hemorrhagic exanthema (palpable round-oval or retiform purpura), with emphasis on the lower extremity and buttocks, and with (ascending pattern) less frequent involvement of the upper extremity, face, and trunk.

Efflorescence type: Initially, 0.1 cm to 5.0 cm bright red spots develop. Later, maculo-papular, deep red, or red-blue to blue-black papules and plaques develop (palpable purpura). With increasing duration, a brown-yellow discoloration of the exanthema begins. Regression after 14-21 days. Total duration 3-16 weeks. In severe forms of the disease: Lentil- to coin-sized, pink- to blue-red, later haemorrhagic, itchy, possibly urticarial spots. Transition to blue-red papules and plaques, vesicles, haemorrhagic blisters, pustules and possibly ulcerations. 5-10% of patients develop a chronic persistent disease with a relapsing course.

Extracutaneous manifestations:

• Arthritides (75% of patients); painful swellings, especially of the ankle joints (my child suddenly can no longer walk!).
• GI manifestations (50-75%): colicky abdominal pain, vomiting, gastrointestinal bleeding (hemorrhagic small vessel vasculitis of the intestinal mucosa).
• Kidneys: glomerulonephritis (30-90%) with micro/macrohematuria indistinguishable from IgA nephritis (histologically: mesangioproliferative glomerulonephritis) which may be complicative as Rapid progressive glomerulonephritis.
• CNS: headache, behavioural disturbances (10-30%).

Acute-phase reactions (high BSG, CRP, leuko- and thrombocytosis) go parallel with the acuteity of vasculitis. There may be circulating immune complexes (lowered complement: CH50,_C3, Ced,_C4), pathological urine sediment or blood in the stool. Activity parameters are the soluble sIL-2 and factor VIII-associated antigen (extent of endothelial damage; see factor VIII below).

There is no specific, diagnostically conclusive parameter from a laboratory point of view. In addition, immunological and molecular biological techniques should be used to exclude hepatitis C/B. Autoantibodies such as ANCA and ANA are associated with both activity and diagnosis.

Edema of the papillary dermis appears in early stages. The epidermis is usually unchanged; occasionally there is exocytosis of neutrophil granulocytes, pustular formation and necrosis. Mostly present is a moderately dense, superficial, perivascularly oriented inflammatory infiltrate of lymphocytes, histiocytes, neutrophil granulocytes and nuclear debris (leukocytoclasia, nuclear dust). Endothelial cells are epitheloid swollen and protrude into the lumen. Fibrin is found in the vessel wall of post-capillary venules. Different densities of perivascular accentuated erythrocyte extravasations can be detected. The exudation can lead to subepidermal blistering and consecutive epithelial necrosis, recognizable by spongiosis and fading keratinocytes.

Granular deposits of IgA in the vessel walls. The IgA deposits are considered to be of major pathogenetic importance for the clinical picture (see also IgA nephropathy)

The diagnosis is based primarily on the typical history/clinical findings(palpable purpura, abdominal and joint pain; age by definition below 21 years, often preceded by an upper respiratory tract infection) and, if necessary, a histological examination of affected skin areas.

Laboratory findings may support the diagnosis, but are non-specific. In addition to an increased erythrocyte sedimentation rate, these include the detection of circulating immune complexes and an increased total IgA. The coagulation parameters are usually unremarkable (DD of purpura!), although global tests of blood coagulation such as the bleeding time (which also covers the vascular component of haemostasis) and the so-called Rumple-Leede test can be pathological. Caution: The Rumple-Leede or capillary resistance test is not specific for angiopathies; abnormal findings can also be found in thrombocytopenias and thrombopathies. If necessary, an increase in antistreptolysin titers may indicate a triggering upper respiratory tract infection.

It is important to monitor visceral organ function, especially the kidneys:

• Renal involvement may be present (renal involvement in the form of glomerulonephritis with hematuriaand proteinuria is present in 20-50% of children).
• Arthritides (ankle > knee > elbow): skeletal scintigram if necessary.
• Intestinal involvement: about 2/3 of children have gastrointestinal complications with recurrent colicky abdominal pain. Abdominal ultrasonography and, if necessary, radiological clarification or endoscopic diagnosis are useful.
• Neurological symptoms: if necessary, cranial CT or cranio-MRI diagnostics are required.

Slight volatile episodes or localised forms of the disease do not generally require treatment. If necessary, glucocorticoid-containing topicals, possibly also under occlusive dressings, e.g. 0.25% prednicarbate (e.g. Dermatop ointment) or 0.1% mometasone (e.g. Ecural ointment) or 0.5-1.0% hydrocortisone cream R120 or 0.1% betamethasone ointment R028 or 0.1% triamcinolone ointment.

Childhood: If the disease occurs in childhood, the prognosis is good, rarely an immunosuppressive therapy is necessary. For prophylaxis of the nephrotic syndrome some authors recommend the early use of glucocorticoids, in severe cases e.g. prednisone 1-3 mg/kg bw/day. There are no objectifiable data on the clinical effect (duration of disease, recurrence) of glucocorticoids in PSH, but only personal experience reports (evidence level D/E).

There are anecdotal reports (see vasculitis below) of dapsone and colchicine (level of evidence E).

If streptococci are detected in the throat swab: benzylpenicillin or penicillin V.

Large-area infestation: Medium to high-dose monotherapy with glucocorticoids (e.g. 80-100 mg prednisolone equivalent). Rapidly eliminate within 14-21 days.

Severe purpura Schönlein-Henoch with systemic involvement(especially kidney involvement) and without self-limiting course: Dual immunosuppressive therapy with glucocorticoids such as prednisolone (e.g. Predni H, Decortin H) 80-200 mg/day and cyclophosphamide as the first choice. With gradual dose reduction, the lowest possible maintenance dose of the glucocorticoid should be aimed at for approx. 3-4 weeks after the skin findings. The combination with cyclophosphamide for a faster reduction of the glucocorticoids is appropriate in the case of extensive findings which require longer therapy.

With the exception of Purpura fulminans favorable prognosis. Recurrences are possible for years. Control of kidney function necessary. Chronic renal insufficiency is possible.

In infancy and childhood, IgA-associated leukocytoclastic vasculitis also manifests as " infantile acute hemorrhagic edema", especially in the facial region (M. Finkelstein).

Another IgA-associated form of vasculitis typical for infants and young children is cocard purpura (M. Seidelmeier): See below Infantile acute hemorrhagic edema.

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