Dermatomyositis Following Pfizer BioNTeh Covid-19 Vaccination: An International Journal of Medical Toxicology and Drug Experience

ABSTRACT

Introduction: Dermatomyositis is an idiopathic autoimmune connective tissue disease. It is typically characterized by proximal muscle weakness and skin rashes. Dermatomyositis is associated with a higher risk of malignancy compared to the general population (1). One case in literature has reported a dermatomysitis post COVID-19 vaccination (2). Objective: Case report. Methods: We report a case of dermatomyositis following Covid-19 immunization, notified to the National Centre of Pharmacovigilance of Tunis in May 2021. Results: A 33 year old woman, with no significant past medical history. She developed in March 2021, two days after 1st dose Pfizer BioNTeh Covid-19 vaccination, a mild facial erythema and ipsilateral auxiliary adenopathy. The evolution was marked by a persistence of the erythema and a regression of the adenopathy In April 2021, 2 days following the 2nd dose, she presented an accentuation of the symptomatology skin erythema and edema in the photo-exposed areas face, neck and upper limbs. As well as a diffuse myalgia in upper and lower limbs. She was afebrile and didn't present itchiness. The patient received intravenous methylprednisolone 1 injection per day for 5 days, followed by 1 mg/kg prednisolone and anti histaminic drugs without amelioration. The diagnosis of dermatomyositis was suspected in view of the persistence of the symptoms 1 month after vaccination and the installation of a proximal muscular deficit. Laboratory studies revealed a high level of creatine phosphokinase (CPK) at 3800 UI/l (< 140) and Lactate dehydrogenase (LDH) at 628 UI/l (< 248). The skin biopsy showed an aspect consistent with a moderate inflammatory myopathy. Autoimmune serology revealed the presence of anti-nuclear antibodies (ANA) (1/100) and a positive anti-Mi-2 antibodies. The patient underwent thorough malignancy screening. Findings of cervico-thoraco-abdomen pelvic scan didn't reveal any evidence for solid organ malignancies or interstitial lung disease. However, the mammogram and ultrasound-guided biopsy has identified an invasive carcinoma. Conclusion: This case showed a dermatomyositis case suspected initially to be associated to mRNA COVID vaccination which was finally related to a breast cancer.