Sweet's syndrome in a patient with rheumatoid arthritis, Sjögren's syndrome and lymph node tuberculosis

Neuro-Sweet disease in a Japanese woman with Sjögren's syndrome

Sweet disease (SD) is a multisystem inflammatory disorder characterised by fever, cutaneous erythematous plaques and aseptic neutrophilic infiltration of various organs. Neuro-Sweet disease (NSD) is a known rare central nervous system complication of SD. We describe a case of a 39-year-old Japanese woman who was diagnosed as NSD associated with Sjögren's syndrome. She was successfully treated with systemic corticosteroid therapy.

Sweet's Syndrome Following Therapy with Hydroxychloroquine in a Patient Affected with Elderly-Onset Primary Sjogren's Syndrome

Sweet's syndrome is an uncommon skin disease characterized by painful polymorphic lesions associated with fever and neutrophilia. When biopsied, these lesions reveal a diffuse infiltrate of mature neutrophils in the papillary dermis. Several drugs can induce Sweet's syndrome (so-called drug-induced Sweet's syndrome (DISS)) but reports of DISS associated with hydroxychloroquine (HCQ) are exceptionally limited. A 72-year-old Caucasian female patient with elderly-onset primary Sjogren's syndrome (EOpSS) but low disease activity presented with an abrupt onset of painful nodular and papular erythematous skin lesions after two weeks of therapy with HCQ 400 mg. A histological examination revealed a diffuse infiltrate of mature neutrophils in the papillary dermis, without vasculitis. After therapy with 25 mg/day prednisone and HCQ withdrawal, the cutaneous manifestations disappeared. When prednisone was permanently discontinued, the primary Sjogren's syndrome (pSS) manifestations worsened and therapy with HCQ 200 mg was reintroduced. In a few days, the same skin lesions reappeared. Withdrawal of HCQ and a new cycle of prednisone resulted in their permanent disappearance. We reported a case of DISS following therapy with HCQ in a female patient affected by EOpSS. According to a literature review, this is the first report of this association.

Insights Into the Pathogenesis of Sweet's Syndrome

Sweet's syndrome, also known as Acute Febrile Neutrophilic Dermatosis, is a rare inflammatory condition. It is considered to be the prototype disease of neutrophilic dermatoses, and presents with acute onset dermal neutrophilic lesions, leukocytosis, and pyrexia. Several variants have been described both clinically and histopathologically. Classifications include classic Sweet's syndrome, malignancy associated, and drug induced. The cellular and molecular mechanisms involved in Sweet's syndrome have been difficult to elucidate due to the large variety of conditions leading to a common clinical presentation. The exact pathogenesis of Sweet's syndrome is unclear; however, new discoveries have shed light on the role of inflammatory signaling, disease induction, and relationship with malignancy. These findings include an improved understanding of inflammasome activation, malignant transformation into dermal infiltrating neutrophils, and genetic contributions. Continued investigations into effective treatments and targeted therapy will benefit patients and improve our molecular understanding of inflammatory diseases, including Sweet's syndrome.

Neutrophilic skin lesions in autoimmune connective tissue diseases: nine cases and a literature review

The pathophysiology of neutrophilic dermatoses (NDs) and autoimmune connective tissue diseases (AICTDs) is incompletely understood. The association between NDs and AICTDs is rare; recently, however, a distinctive subset of cutaneous lupus erythematosus (LE, the prototypical AICTD) with neutrophilic histological features has been proposed to be included in the spectrum of lupus. The aim of our study was to test the validity of such a classification. We conducted a monocentric retrospective study of 7028 AICTDs patients. Among these 7028 patients, a skin biopsy was performed in 932 cases with mainly neutrophilic infiltrate on histology in 9 cases. Combining our 9 cases and an exhaustive literature review, pyoderma gangrenosum, Sweet syndrome (n = 49), Sweet-like ND (n = 13), neutrophilic urticarial dermatosis (n = 6), palisaded neutrophilic granulomatous dermatitis (n = 12), and histiocytoid neutrophilic dermatitis (n = 2) were likely to occur both in AICTDs and autoinflammatory diseases. Other NDs were specifically encountered in AICTDs: bullous LE (n = 71), amicrobial pustulosis of the folds (n = 28), autoimmunity-related ND (n = 24), ND resembling erythema gyratum repens (n = 1), and neutrophilic annular erythema (n = 1). The improvement of AICTDS neutrophilic lesions under neutrophil targeting therapy suggests possible common physiopathological pathways between NDs and AICTDs.