E24. Myositis Following Vaccination: An Unexpected Risk of Travel

Abstract

Background: Drug-induced myositis is well described in medical literature, with a variety of agents implicated. We describe a case following vaccination for HAV and typhoid in preparation for travel abroad; this has not previously been documented as a causative agent. The patient recovered well, without the need for immunosuppressive treatment. Method(s): A 21 year old student with a previous history of cervical dysplasia [cervical intraepithelial neoplasia (CIN 1) 1] and polycystic ovarian syndrome presented to the acute medical take with a history of subacute onset bilateral quadriceps pain and weakness, which had rapidly progressed until she required a wheelchair to mobilize; she had similar but less severe symptoms in her arms. Examination revealed symmetrical proximal muscle tenderness and weakness affecting the legs more than arms. Systemic examination, including skin, was otherwise unremarkable. Careful history elicited vaccination for HAV and typhoid within the preceding fortnight, but no other symptoms or recent changes in usual activity to suggest another cause. Investigations demonstrated creatine kinase (CK) of 1980 IU/l with no evidence of macro-CK on further testing. Spirometry was normal, as was EMG testing a few days after presentation. Full blood count, urea and electrolytes, liver function tests, thyroid function tests, immunoglobulins, viral screen, inflammatory markers and bone profile were essentially normal apart from a marginally low vitamin D, and raised aspartate transaminase at 55. Troponin T was normal, and subsequent autoimmune profile, including extended myositis screen was also within normal range. MRI of the thighs showed subtle increased signal on the short Ti inversion recovery sequence within the left lateral thigh muscles. Biopsy of vastus lateralis was carried out, with no evidence of glycogen storage disease or inflammatory myopathy, although this was carried out 9 days after initial presentation, by which time the patient, and the CK titre had improved markedly. Given the history of CIN, a transvaginal US scan and cervical biopsies were performed, which showed no concerning features. The patient recovered spontaneously, without the need for immunosuppression and 2 weeks after leaving hospital CK had normalized. Result(s): Drug-induced myopathy may be medicated by direct myotoxicity or immunologically mediated. Typical onset is within weeks to a few months after exposure, and resolution occurs generally within the same timeframe. Over 150 drugs have been described to cause myopathy, but a literature search did not reveal any previously reported cases following HAV /typhoid vaccination. Although biopsy was normal, the previous absence of muscle symptoms, temporal relationship, lack of alternative cause and clinical course (spontaneous recovery within a few weeks) strongly suggest drug-induced disease. Conclusion(s): This is the first reported case of myositis associated with HAV and typhoid vaccination. When taking a history, clinicians should ensure that a drug history includes recent vaccinations.