Systemic Lupus Erythematosus Presenting With Severe Hypothyroidism and Extensive Pericardial Effusion in a Child.

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which may be associated with other autoimmune diseases, like autoimmune hypothyroidism. Both disorders can involve the cardiovascular system and cause pericardial effusion with cardiac tamponade. Herein, we describe a young eight-year-old female patient who initially presented with periorbital edema, cold intolerance, fatigue, and papular skin rash that was present on the face and the chest and was found to have significant pericardial effusion along with bilateral pleural effusion. Further laboratory investigation done in the hospital revealed severe hypothyroidism and positive SLE antibodies (antinuclear antibodies [ANA], antidouble strand DNA [anti-ds-DNA], and Sjögren's syndrome antibodies A and B [SS-A and SS-B]). She was administered levothyroxine and pulse methylprednisolone, which significantly improved her condition. She was discharged on maintenance therapy with regular follow-ups with a multidisciplinary team.