This case describes the resolution of refractory chronic idiopathic urticaria (CIU) with setmelanotide in a patient with Bardet-Biedl Syndrome (BBS). While setmelanotide is approved for syndromic obes Show more
This case describes the resolution of refractory chronic idiopathic urticaria (CIU) with setmelanotide in a patient with Bardet-Biedl Syndrome (BBS). While setmelanotide is approved for syndromic obesity, this report highlights a novel anti-inflammatory effect potentially mediated by melanocortin-4 receptor (MC4R) agonism, expanding current understanding of its immunomodulatory role in mast cell-mediated disease. The patient presented with lifelong hyperphagia and class III obesity beginning in childhood, along with multiple features fulfilling BBS clinical criteria: visual impairment with night vision difficulties, renal abnormalities with proteinuria, irregular menses with polycystic ovaries, and neurodevelopmental delay. She also reported refractory CIU with pruritic hives occurring several times weekly despite dual antihistamine therapy. On examination, BMI was 40.5 kg/m Genetic testing revealed a heterozygous pathogenic Setmelanotide produced durable remission of refractory CIU in a patient with BBS, suggesting MC4R agonism may exert immunomodulatory effects beyond weight regulation. This finding underscores the broader potential of precision therapies for rare obesity syndromes to reveal new mechanisms of inflammation control. Show less