Summary
Urticaria is a common, pruritic skin condition with multiple causes and
can have a significant impact on quality of life. In this paper we
present a case of acute urticaria secondary to hyperthyroidism. This
link appears to be due to the autoimmune thyroid cascade (particularly
IgE anti-thyroid peroxidase (TPO) antibodies) sensitising mast cells for
activation and histamine release. Although anti-histamines and steroids
are first-line treatment, identifying the “causative” factor is not
easy in hyperthyroid patients due to the independent links urticaria
shares with both carbimazole and thyrotoxicosis.