Page 172 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

148 Ezgi Deniz Batu and Seza Ozen

perianal area, polymorphous exanthema, bilateral conjunctival injection, changes of lips and
oral cavity or injection of oral and pharyngeal mucosa, and cervical lymphadenopathy.

In the case of fever or coronary artery disease detected by echocardiography, fewer than
four of the remaining five criteria would be sufficient to classify a patient as having KD [24].

Polyarteritis Nodosa

PAN is a necrotizing vasculitis characterized by aneurysmal nodules along the walls of
predominantly medium-sized arteries and multiorgan involvement that affect individuals of
all ages [30]. The estimated annual incidence is 2 to 9 per million in adults in Europe and the
United States [34].

The ACR criteria for cPAN requires at least three of the following 10 criteria including,
granulocyte or mixed leukocyte infiltrate in an arterial wall on biopsy, arteriographic
abnormalities, livedo reticularis, myalgia, diastolic blood pressure >90 mmHg, mono or
polyneuropathy, elevated blood urea nitrogen or creatinine, testicular pain or tenderness,
hepatitis B reactants, and weight loss of >4 kg [20].

Modified forms of ACR criteria have been used for cPAN classifications [35, 36]
however, they were found insufficient prompting a revision. The criterion of hepatitis B virus
(HBV) serology positivity, which is unusual in cPAN due to vaccination protocols [10], was
removed.

According to the Revised 2012 CHCC nomenclature [2], vasculitis related to HBV
infection was classified under “vasculitis associated with probable etiology”. A new item in
the criteria was to designate the typical histopathology or angiographic abnormalities as a
mandatory criterion [22]. After this first revision, cPAN classification criteria took final form
with the removal of the criteria for the signs and symptoms of vasculitis in specific organ
systems, as well as testicular pain and tenderness [24]. With all these modifications, the
criteria achieved a sensitivity of 89.6% and a specificity of 99.6% [24].

The classification of cPAN under the Ankara 2008 criteria required mandatory histologic
evidence of necrotizing vasculitis in medium- or small-sized arteries or angiographic
abnormalities including conventional angiography if magnetic resonance angiography (MRA)
was negative, plus one of the following five criteria including, skin involvement, myalgia,
hypertension, peripheral neuropathy, and renal involvement [24].

Cutaneous PAN

Cutaneous PAN (CPAN) is a form of PAN affecting small- and medium-sized vessels
limited to the skin [37]. It constitutes a large group in pediatric practice with approximately
one-third of the children with PAN categorized as CPAN in one international survey of
childhood vasculitis [10].

Although there are no formal classification criteria, in 2005 [22] CPAN was
characterized by subcutaneous nodular, painful, non-purpuric lesions with or without livedo
reticularis, and without systemic involvement except for myalgia, arthralgia, and non-erosive
arthritis.

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