POLYARTERITIS NODOSA

Polyarteritis nodosa (PAN) is a rare but severe necrotizing vasculitis of small- and medium-sized arteries, although most cases present beyond childhood.

Etiology is unknown, though occurrence of PAN after viral and streptococcal infections as well in chronic HBV disease suggests probability of post-infectious autoimmune response in susceptible individuals.

Clinical manifestations are usually preceded by acute febrile illness and depend on site of involvement. Most cases initially present with unexplained pyrexia, arthralgia, myalgia and wasting, followed by system­specific features, e.g. (a) skin involvement with Linear purpura, edema and painful nodules along the course

TABLE 24.13: Diagnostic (Ozen) criteria for pediatric PAN

Necrotizing vasculitis on histopathology or

Vascular aneurysm/stenosis/occlusion* on angiography With any one of the following:

• Skin involvement

• Myalgia/Muscle tenderness

• Hypertension

• Peripheral neuropathy

• Renal involvement

*Of small or medium arteries

Abridged from EULAR/PRINTO/PRES criteria 2008

TABLE 24.14: Diagnostic criteria for childhood Takayasu disease

• Angiographic abnormalities, With

• Any one of the following criteria:

- Weak peripheral pulses or claudication of limbs

- BP difference between arms or legs gt;10 mm Hg

- Bruits over the aorta or its major branches

- Hypertension

- Elevated acute phase reactant (ESR, CRP)

Abridged from EULAR/PRINTO/PRES criteria 2010

of vessels, (b) renal involvement with hypertension, hematuria or proteinuria, (c) GIT involvement with severe abdominal pain due to mesenteric vasculitis, (d) coronary involvement with myocarditis, cardiomegaly or CCF, and

(e) CNS involvement with stroke, psychosis or peripheral neuropathy.

Diagnosis rests on Ozen criteria (Table 24.13), including either (a) biopsy of skin nodules or kidney showing signs of segmental fibrinoid necrosis of medium-sized arteries, or (b) angiographic studies to demonstrate aneurysms of renal or celiac vessels, along with at least one clinical feature/organ involvement.

Treatment includes long-term immunosuppressive therapy with steroids or cyclophosphamide. Course of disease depends on the severity and extent of vascular involvement.

24.4.5