Polyarteritis nodosa: an atypical presentation.

To cite: Andrade CA dos S, Vasconcelos A, Pinto JC. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2015-209564 DESCRIPTION Polyarteritis nodosa is a systemic necrotising vasculitis involving the small and medium arteries. Men aged between 40 and 60 years are more frequently affected and histological evidence of vasculitis in the involved organs is necessary for diagnosis. 2 A 55-year-old woman presented with a history of fever and painful skin lesions in the right leg, associated with progressive weakness and sensory loss in the affected limb. Physical examination revealed multiple hypochromic spots over the face and limbs (figure 1), a rounded lesion with a necrotic centre and inflammatory broadsides on the right knee (figure 2), and two haemorrhagic bullous lesions on the right foot (figure 3). These lesions were associated with swelling, redness and warmth of the right limb. A distal paresis of the right limb, absence of right ankle reflex, decreased vibratory sensation and hypoesthesia below the right knee were observed during neurological examination. Because of weakness in the dorsiflexors of her feet and toes, the patient had a high-stepping gait, lifting her knees to avoid dragging her toes on the floor. Haematological investigations showed normocytic and normochromic anaemia, leucocytosis with neutrophilia, and elevated C reactive protein and erythrocyte sedimentation rate. Electromyography showed a common sciatic mononeuropathy. A skin biopsy of the knee lesion was performed and the