Sweet Syndrome and Hashimoto Thyroiditis: A Case Report and Review of the Literature

ABSTRACT Objective Sweet syndrome (SS) is characterized by an inflammatory rash that has been associated with a number of drugs and malignant, inflammatory, and infectious conditions. Rare accounts of Hashimoto thyroiditis (HT) presenting with SS exist in the literature. HT is usually identified after the onset of skin lesions and without signs of overt thyroid dysfunction, and the stage of thyroid disease stage at presentation is variable. Methods A search of the PubMed database was performed using search criteria involving combinations of “Sweet syndrome” and “Hashimoto thyroiditis,” “autoimmune thyroiditis,” or “thyroiditis,” and the search was filtered for clinical case reports. Five case reports were identified to describe the coexistence of Sweet syndrome and Hashimoto thyroiditis, and full-text versions of these reports were obtained and reviewed. Of note, cases involving subacute or other types of thyroiditis were excluded. Results A 57-year-old man presented with painful eruptions on his hands; he was initially treated with antibiotics for presumed cellulitis without relief. Skin biopsy later confirmed SS and subsequent workup identified underlying HT with an elevated thyroid-stimulating hormone of 19.24 mU/L (normal, 0.30 to 4.30 mU/L) and positive thyroid peroxidase (TPO) antibody at 236.4 IU/mL. Conclusion Thyroid function tests should be universally evaluated in the workup of SS, and it may be appropriate to test for TPO antibodies even in the absence of objective thyroid dysfunction. Both SS and HT show immune diathesis, so further work should be undertaken to establish whether a common immunologic trigger exists.