(Kiosk 2) Sweet Syndrome: A Case Report

Case Diagnosis: Adult-Onset Still’s Disease (AOSD) re-diagnosed as Sweet Syndrome.

Case Description or Program Description: The patient presented to the hospital with two weeks of recurrent daily fevers, acute onset polyarthritis, and rash. Labs showed elevated ESR, CRP, WBC, and ferritin. He was initially diagnosed with Still’s Disease and started on high-dose prednisone. He saw improvement of pain and fevers so was discharged home without therapy needs.

Setting: Academic medical hospital, inpatient evaluation and outpatient follow up.

Assessment/Results: On Rheumatology follow-up, the patient had increasing leukocytosis while on steroids. He was readmitted to the hospital with return of fever, return of pain in hands and feet, and a new rash (periorbital and dorsal aspects of hands). He had a punch biopsy of skin which showed “neutrophilic dermatosis, consistent with Sweet Syndrome”. He was discharged home without therapy needs and improved on steroid taper. Pain and rash resolved. Imaging incidentally showed mediastinal and hilar lymphadenopathy, for which workup is ongoing.

Discussion (relevance): Sweet Syndrome and AOSD are febrile, inflammatory conditions with similar manifestations such as high fever, neutrophilia, rash, and arthralgia. Additionally, steroids are the first line of treatment for both. Although they present similarly, differences do exist. One of the key differences is the histopathology of the cutaneous rash. In AOSD, there is dermal edema with mixed inflammatory infiltration of the perivascular areas. Sweet Syndrome is identified by dermal papillary edema with abundant neutrophilic infiltrates. It is important to distinguish between the two since Sweet Syndrome could be caused by an underlying malignancy.

Conclusions: Sweet Syndrome and AOSD are inflammatory conditions with musculoskeletal manifestations, which make them important components of a differential diagnosis from a physiatrist’s perspective. In particular, Sweet Syndrome can be indicative of an underlying malignancy, making its diagnosis an important one to consider.