Systemic flare and cutaneous ulceration following cytomegalovirus infection in a patient with anti-melanoma differentiation-associated protein 5 (MDA5) associated myositis: Diagnostic challenge during the time of coronavirus disease (COVID-19) pandemic.

Background: Anti-melanoma differentiation-associated protein 5 (MDA5) associated idiopathic inflammatory myopathy (IIM) often manifests with minimal muscle weakness and rapidly progressive interstitial lung disease (RP-ILD) with a poor prognosis. The clinical presentation may be varied in different ethnic groups. The ongoing coronavirus disease (COVID-19) pandemic has made management even more challenging as certain manifestations may be difficult to diagnose remotely. Aim of the work: To throw light on the rare association of CMV infection in established anti-MDA5 myositis with severe consequences. Similar cases were presented and compared. Case report: A 42-year-old lady presented with heliotrope rash, periorbital edema, ulcerated Gottron's papules, proximal muscle weakness and intermittent fever of six-month duration. Anti-MDA5 antibodies were positive. Active disease, including myocarditis and RP-ILD, were challenging to diagnose on teleconsultation. Upon initiating tofacitinib, cytomegalovirus (CMV) polymerized chain reaction (PCR) came positive. Ganciclovir was started with the possibility of viral activation being the potential driving force for interferon pathway activation and dermatomyositis (DM) flare, but the patient succumbed to the illness. Conclusion: Viral triggers are known to induce autoimmune disease in the genetically predisposed. However, CMV infection in established anti-MDA5 myositis is uncommon and further association with myocarditis is a rare occurrence. Ulcerated Gottron's and periorbital oedema may carry a sinister connotation in Indians with anti-MDA5 DM, with worse manifestations such as myocarditis- which albeit rare, can be fatal.