EP11 An unusual presentation of Sweet syndrome

Abstract

Abstract Background Sweet syndrome (acute febrile neutrophilic dermatosis) is a rare inflammatory disorder affecting individuals between the ages of 30 and 60. It is characterised by painful, edematous, and erythematous skin papules, plaques, or nodules. Fever and leukocytosis (neutrophilia) frequently accompany the skin lesions. A majority of cases are idiopathic but there is a significant proportion attributed to malignancy or medications. Our case is peculiar because of an unusual presentation of a 12-month history of undifferentiated inflammatory arthritis before manifestation as Sweet syndrome. The mainstay of treatment is corticosteroids, although spontaneous resolution has been reported. Treatment of an underlying medical cause may lead to an improvement in Sweet syndrome. Methods A 57-year old British male presented with a 1-year history of intermittent joint pain and swellings in both upper and lower limbs. He had been treated with short courses of oral corticosteroids for undifferentiated inflammatory arthritis. As part of his extensive investigations whilst as a private outpatient, a knee MRI raised suspicion of malignancy, leading him to be referred to haematology and having a bone marrow examination. He was admitted with fever, polyarthritis and skin rash in form of papules around elbows and pustules on tip of some fingers. He was started on empirical antibiotics and reviewed by the Dermatology and Rheumatology teams. A skin biopsy was performed. He continued to have temperature spikes throughout admission and inflammatory markers remained elevated despite being on antibiotics. Results Full blood count showed leucopenia and Iron deficiency anaemia MCV 78 Iron 6 Transferin saturation 15% .Electrolytes, renal and liver function were normal. CRP was elevated at 190 mg/L. Acute infection screen including blood cultures and viral screen were negative. Immunology tests including Anticcp, ANA, ENA, and ANCA were all unremarkable. Echocardiogram was normal. The bone marrow biopsy showed hypercellular marrow with reactive appearances. Full body CT showed no focal signs of infection, lymphadenopathy or malignancy, with the positive findings being only a mildly enlarged spleen. Skin biopsy was consistent with a neutrophilic dermatosis such as Sweet syndrome. Conclusion This case highlights the atypical presentation of classical Sweet syndrome with no obvious underlying cause and no rise in neutrophil count. It also raised our awareness that splenomegaly can be part of Sweet syndrome and does not necessarily mean an underlying haematological disorder. The patient showed remarkable improvement with resolution of synovitis, fever and the rash once restarted on corticosteroids. He has been discharged from haematology as his blood count and CRP have normalised. Although arthralgia and arthritis have been reported in Sweet syndrome, we believe that this the first case in the literature where Sweet syndrome has manifested as undifferentiated inflammatory arthritis. Disclosures A.A.M. Mohamednour None. D. Teo None. V. Rastu None. K. Sunmboye None.