What clinical findings in this patient led to the suspicion of Polyarteritis nodosa?

  • age 40 to 60 years
  • myalgia or arthralgia
  • mononeuritis multiplex
  • paresthesia
  • muscle tenderness
  • skin manifestations
  • diastolic blood pressure >90 mmHg 

Other clinical features that can point towards PAN include:

  • blood transfusion at a time before routine screening for hepatitis B virus (HBV)
  • previous or current intravenous drug abuse
  • recent hepatitis B virus (HBV) infection
  • fever
  • weight loss
  • abdominal pain
  • testicular pain

The American College of Rheumatology (ACR) has established ten criteria for the classification of polyarteritis nodosa in a patient with a vasculitis. A sensitivity and specificity for the diagnosis of polyarteritis of 82 and 87 percent, respectively, has been found in the patient with a documented vasculitis in whom at least three of the following criteria are present(Lightfoot et al. 1990):

1.     Otherwise unexplained weight loss greater than 4 kg

2.     Livedo reticularis

3.     Testicular pain or tenderness

4.     Myalgias (excluding that of the shoulder and hip girdle), weakness of muscles, tenderness of leg muscles, or polyneuropathy

5.     Mononeuropathy or polyneuropathy

6.     New-onset diastolic blood pressure greater than 90 mmHg

7.     Elevated levels of serum blood urea nitrogen (>40 mg/dL or 14.3 mmol/L) or creatinine (>1.5 mg/dL or 132 micromol/L)

8.     Evidence of hepatitis B virus infection via serum antibody or antigen serology

9.     Characteristic arteriographic abnormalities not resulting from noninflammatory disease processes

10.   A biopsy of small- or medium-sized artery containing polymorphonuclear cells 

What types of skin lesions can be seen in patients with Polyarteritis nodosa?

Skin manifestations of PAN may include tender erythematous nodules, purpura, livedo reticularis, ulcers, and bullous or vesicular eruption(Pagnoux et al. 2010).

Skin lesions may be focal or diffuse and are more frequently and often more marked over the lower extremities. Limb edema is common. Progressive skin involvement may be severe, including infarction and gangrene of the fingers, toes, or other areas and ulceration extending into the subcutaneous tissue. However, digital and limb ischemia often reflects involvement of arteries larger than “medium-sized” skin vessels.

References:

Lightfoot et al. 1990. The American college of rheumatology 1990 criteria for the classification of polyarteritis nodosa. Arthritis & Rheumatism 33(8), pp. 1088–1093. doi: 10.1002/art.1780330805.

Ntatsaki et al. 2014. BSR and BHPR guideline for the management of adults with ANCA-associated vasculitis. Rheumatology 53(12), pp. 2306–2309. doi: 10.1093/rheumatology/ket445.

Pagnoux et al. 2010. Clinical features and outcomes in 348 patients with polyarteritis nodosa: A systematic retrospective study of patients diagnosed between 1963 and 2005 and entered into the French vasculitis study group database. Arthritis & Rheumatism 62(2), pp. 616–626. doi: 10.1002/art.27240.

Ribi et al. 2010. Treatment of polyarteritis nodosa and microscopic polyangiitis without poor‐prognosis factors: A prospective randomized study of one hundred twenty‐four patients. Arthritis & Rheumatism 62(4), pp. 1186–1197. doi: 10.1002/art.27340.