RESUMO
ABSTRACT: Mixed connective tissue disease (MCTD) is a systemic autoimmune disease with features overlapping multiple autoimmune disorders. One study found that over 55% of patients with MCTD experienced neuropsychiatric symptoms, the most common of which was an "aseptic meningitis-like syndrome." We present a case of a 17-year-old adolescent girl presenting with abnormal speech and behavior, auditory hallucinations, and paranoid delusions after an isolated episode of fever. She was treated for her psychotic symptoms but later developed symptoms resembling neuroleptic malignant syndrome. An antibody screen revealed elevated anti-U1-ribonucleoprotein antibodies with a possible diagnosis of MCTD. She finally responded to steroid therapy. To our knowledge, this is the first reported case of MCTD initially presenting with psychosis. A diagnosis of autoimmune disorders should be kept in the differential of similar clinical presentations including connective tissue disorders and autoimmune thyroid conditions.
