A Tattoo Reveals Its Cold Secret

A labourer in his forties complained of pain and dusky discolouration over his ankles and feet for 6 weeks before admission to hospital. He had also developed patchy and asymmetric numbness and weakness in all four limbs, and a rash on his legs [Fig. 1] accompanied by digital ischaemic lesions affecting his fingers and toes. He used to be an intravenous drug user. Following a prolonged period of drug abstinence, 2 weeks before the onset of his symptoms, he had sniffed cocaine. Neurological examination revealed ulnar and common peroneal palsies [Figs 1 and 2] suggesting mononeuritis multiplex, and nerve conduction studies [Fig. 3] confirmed a very severe active axonal sensory and motor polyneuropathy with multifocal features. The distribution of nerve involvement was non-confluent, and electromyography showed severe active denervation, in keeping with a vasculitic neuropathy. Skin biopsy showed acute leukocytoclastic vasculitis involving small vessels in the papillary dermis. [Fig. 4].