Sweet syndrome caused by oral contraceptives

Drug-induced Sweet's syndrome: A case/non-case study in the French pharmacovigilance database

AIMS

Sweet's syndrome is an acute febrile neutrophilic dermatosis first described in 1964 by Robert Douglas Sweet. The pathophysiological mechanism is not fully established; however, several cases of Sweet's syndrome have been reported following drug administration.

METHODS

To investigate the existence of pharmacovigilance signals between drugs and the occurrence of Sweet's syndrome, we performed a case/non-case study on reports of 'acute febrile neutrophilic dermatosis' registered in the French pharmacovigilance database. Reporting odds ratio (ROR) with its 95% confidence interval were calculated.

RESULTS

Amongthe 994 789 reports recorded in the database, 136 were Sweet's syndrome, of which 50.7% were men and the median age was 59 years (range 15-91). A total of 224 drugs were mentioned as suspects: 21.0% were antibacterials, 19.2% were antineoplastics and 12.1% were immunosuppressants. Median time to onset from drug initiation to the development of Sweet's syndrome was 15 days (range 1-1095). The highest RORs were observed with bortezomib (74.04 [40.8-134.2]), azacitidine (72.14 [29.4-176.9]), perfilgrastim (67.05 [21.2-211.6]), azathioprine (55.46 [34.8-88.4]) and bendamustine (35.84 [11.4-112.8]).

CONCLUSIONS

Pharmacovigilance signals have been observed between the occurrence of Sweet's syndrome and colony-stimulating factors, immunosuppressants, antineoplastics and antibiotics. Clinicians should be aware of the potential associations with these drugs and should be encouraged to report any case of drug-induced Sweet's syndrome.

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.

Lymphocytes in Sweet syndrome: A potential diagnostic pitfall

BACKGROUND

Patients with Sweet syndrome (SS) have acute onset of cutaneous lesions with characteristic histopathology (dense and diffuse neutrophilic infiltrate, dermal edema, leukocytoclasis and no vasculitis) accompanied by systemic symptoms. Sometimes, only skin lesions with classic histopathologic features are seen. Although SS is considered to be a "neutrophilic dermatosis," lymphocytes are also seen on histological examination.

METHODS

We evaluated the cellular infiltrate in 9 biopsies from SS lesions with routine staining and immunohistochemistry.

RESULTS

Lymphocytes were present in all biopsies in variable amounts, often exceeding the number of intact neutrophils. Prominent fragmentation of neutrophils rendered some biopsies "lymphocyte-rich" on routine histologic evaluation. Myeloperoxidase was helpful in highlighting the inconspicuous neutrophilic fragments in these cases. Lymphocytes were highlighted with immunohistochemistry, and had a CD3+, CD4+, CD20(-) immunophenotype, with rare CD8+ lymphocytes.

CONCLUSION

Awareness of the lymphocytic component of SS is important to avoid diagnostic errors, especially in subcutaneous lesions of SS, in which the lymphocytic infiltrate predominates in the upper parts of the dermis, while the typical neutrophilic infiltrate may be seen only in the deeper dermis and subcutis. The lymphocytic component may potentially help to differentiate lesions of SS from neutrophilic urticarial dermatosis, which has not been reported to contain a significant lymphocytic population.