Sweet's syndrome: A review from two tertiary hospitals in Malaysia

Sweet's syndrome (SS) also known as acute febrile neutrophilic dermatosis, is an uncommon disease characterised by acute onset of tender, violaceous or erythematous, oedematous papules, nodules or plaques, with fever. It is classified into classic, malignancyassociated, and drug-induced subtypes.The aims of this study is to evaluate the subtypes, clinical features, laboratory profiles, and treatment of patients with SS.We did a retrospective medical record review of all patients with SS from July 2014 to July 2018 at Hospital Queen Elizabeth and Hospital Pulau Pinang, both tertiary hospitals in Malaysia.Twenty-nine patients were included. Approximately half of the patients (15) were females with a mean age of onset of 50.93 (± 11.52) years. The most common subtype was classic (62.0%) followed by malignancy-associated (31.0%) and drug-induced (6.9%). Among the patients with the classic subtype, infective-related causes (50.0%) were the most common. Among the patients with malignancy, eight had haematological malignancy and one had a solid tumour. Two-third of the malignancies were diagnosed within a year after the diagnosis of SS. Eight of our patients in Sabah had mycobacterial infections with three having concomitant haematological malignancies. Patients with malignancy-associated SS had lower mean haemoglobin (p=0.018) and mean platelet count (p=0.031). Itch was associated with the presence of pustules (p=0.038). Histopathological examination of all skin lesions showed dermal neutrophilic infiltrates and 25 (86.2%) of them had papillary dermal oedema. The study was limited by its retrospective design. The sample size was small likely due to the uncommon occurrence of this condition.SS is an uncommon dermatosis with distinctive clinical and histopathological features. Screening for underlying malignancy is essential especially for those who present with anaemia, thrombocytopenia, and pathergy phenomenon. Mycobacterial infection should be considered in this region due to high tuberculosis burden.