Contributed by Michelle Heayn, MD, PhD and Octavia M. Peck Palmer, PhD
A woman in her late thirties who is 15 weeks pregnant (G1P0) visits the allergy and immunology clinic. She has a history of positive anti-thyroid antibody (subtype unkown) which was diagnosed ten years prior and is treated with Synthroid. She complains of urticaria, flushing, and cramping abdominal pain with exercise. These symptoms can also be evoked by hot showers and urticaria occasionally develop in areas of skin exposed to pressure or friction. The symptoms began occurring occasionally twenty years ago and have been progressively increasing in frequency and severity. The symptoms are generally well controlled by daily doses of fexofenadine and ranitidine taken thirty minutes prior to exercising. The patient also states that she experiences at least two mild headaches per week. She is concerned about the safety of her current medication regimen given her pregnancy. The physical exam is non-contributory. Laboratory studies are included in Table 1.
Table 1. Patient baseline laboratory studies.