PP09.13 – 2832: A case of acute rhabdomyolysis with intermittent myositis and persistently low levels of Parvovirus B19 infection

Abstract

Objective Persistent parvovirus B19 infection has been reported as an uncommon cause of fatigue and arthralgia in adults. Here, we present the first case of an otherwise healthy nine-year-old child with evidence of persistent parvovirus B19 infection associated with a relapsing myopathy, an acute episode of severe rhabdomyolysis at age eight. Methods This 9 year old girl has 5 year history of recurrent episodes involving painful calves, reduced activity, urinary symptoms with dysuria and frequency. Her activity level is markedly reduced during such episodes with tip toe walking. These episodes occur at frequency of 1–2 times every year and have never been investigated in past, have been managed at primary level as presumed UTI's, although there have been no positive cultures. At the age of 8 years, referred for the first time with lower limbs aches and pains and cola coloured urine. Examination revealed slight tenderness of calves, tip toe walking, but rest of neurology was normal. Results Investigations suggested acute rhabdomyolysis and her CK was above 52,000 U/L, LDH 11,960. She was managed conservatively and responded well quickly. Her CK and LDH normalized quickly, however CK has remained slightly elevated since then. (355 U/L 5 months ago). Acylcarnitines, free carnitine, organic acids, amino acids, VLCFA, Fatty acid oxidation flux results were essentially normal. A quadriceps femoris muscle biopsy showed no glycogen or lipid storage, but changes suggestive of chronic low grade infection. Parvovirus B19 was positively identified by customized Taqman low-density array (TLDA) assay in muscle. Serology was positive for parvovirus B19 IgG, but negative for IgM. Conclusion We suggest this is a case of recurrent rhabdomyolysis due to persistent low level parvovirus B19 infection. The result of a very detailed rhabdomyolysis panel is still awaited, but so far no genetic cause has been found.