Page 406 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

380 Rami N. Al-Rohil and J. Andew Carlson

Immunofluorescence analysis of a tissue biopsy of involved skin lesions is indispensable.
The commonest immunoreaction found in vessels by DIF is C3, followed by IgM, IgA and
IgG, and fibrin deposits [1, 4]. The type of Ig and pattern of deposits in DIF will be of
additional diagnostic value. For example predominance of IgA in HSP/IgAV (Figure 11) will
direct attention to renal involvement. Basement membrane zone or keratinocyte nuclear or in
vivo antinuclear antibody (ANA) and IgG immunoreactions are found in vasculitides
associated with CTD such as LV. The finding of basement membrane zone immunoreactions
occurs in those with HUV/C1q and CTD. In addition, IgM deposition in blood vessels may be
readily seen in patients with CV or RAV and circulating RF or monoclonal production of
IgM.

Further laboratory evaluation of patients with cutaneous vasculitis should be guided by
the history and physical examination as to the possibility of preexisting or concomitant
systemic illness, including relevant drug and infectious exposures [1, 15]. Clues to the
presence of underlying systemic illness include night sweats, weight loss, dry eyes ad mucous
membranes, photosensitivity, facial cutaneous eruption, oral lesions, muscle weakness,
mononeuritis, arthralgia, myalgia, fever, hemoptysis, shortness of breath, cough, wheezing,
eye or ear symptoms, sinusitis, hoarseness, numbness or paresthesia, abdominal or testicular
pain, melena, and hematuria [1,15].

Figure 11. Petechial leg eruption in HSP/IgAV. Skin biopsy shows neutrophilic small vessel vasculitis
restricted to the superficial dermis. Direct immunofluorescence demonstrates IgA vascular deposits.

Patients with suspected of a primary vasculitides should undergo baseline complete blood
cell count (CBC) with differential, blood urea nitrogen (BUN), creatinine, liver function
panel, urinalysis, stool guaiac, hepatitis B (HBV) and C virus (HCV) serology, ANA,
cryoglobulins, and ANCA testing. Other studies include blood cultures and echocardiography
when fever or heart murmurs are present, anti-streptolysin O titers in children and adults with

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