An Unusual Association between Sweet's Syndrome and Metastatic Papillary Follicular Thyroid Carcinoma
A 79-year-old female presented with a sore throat and non-productive cough for 10 days, a rash for 7 days, and fever for 4 days. The rash was painful and initially began on the palms of both hands with subsequent proximal spread to the torso. At the same time, the patient developed a similar rash on the plantar aspects of both feet with progression to the lower legs. The patient also reported a rash within her mouth that she noticed on the day of presentation.\nThe patient's medical history was significant for PFTC (diagnosed 2 months prior to admission) with metastases to bilateral lungs, ribs, and clavicles. She underwent a total thyroidectomy 1 month prior to admission and has since been receiving radioiodine therapy. Her family history was significant for multiple first-degree family members with thyroid carcinoma of unknown pathology.\nOn physical exam, the vital signs were remarkable for a fever of 100.6°F. The remainder of the exam was significant for the rash that manifested as distinct and intact tender pustules of varying (5~7 mm, diameter) sizes as well as several erythematous halos with surrounding edema. These findings were present on the dorsal and palmar surfaces of the hands () and extended to the mid-radial/ulnar region. The rash was also present on the abdomen, bilateral heels, and on the mucosal surface superior to the lower labial frenum.\nInitial laboratory results revealed leukocytosis (17,100 cells/mm3) and neutrophilia (80%). A Group A streptococcal throat culture and anti-streptolysin O (ASLO) titers were positive with an ASLO of 894 IU/ml, and an erythrocyte sedimentation rate (ESR) of 100. Anti-neutrophil cytoplasmic antibody, anti-nuclear antibody, varicella- zoster direct fluorescent antigen, a syphilis screen, and blood/viral/wound/urine cultures were all negative. In light of the patient's painful rash on the hands, an X-ray of the left hand was performed and demonstrated osteoarthritic changes in the digits.\nUpon admission, the patient was empirically started on vancomycin for possible methicillin-resistant Staphylococcus aureus infection. The patient remained febrile with an increase in the leukocytosis (29,200 cells/mm3), and ceftriaxone was added on hospital day 4; initial and subsequent blood and urine cultures were repeatedly negative. Given the persistent rash and fever, biopsies of the upper extremity lesions were taken and dermatopathology demonstrated superficial perivascular dermatitis with deeper sections revealing pustular vasculitis consistent with SS (, pathology showing SS). Following the histopathologic diagnosis of SS, prednisone was started with improvement in pain and swelling noted by the patient. Within 1 day of starting prednisone, the patient became afebrile. She received 10 days of steroid therapy, which resulted in resolution of the diffuse pustules on follow-up visits.