Isotretinoin-associated Sweet's syndrome: a case report

Systemic isotretinoin therapy and central macular and choroidal thicknesses in acne vulgaris: is there any association?

PURPOSE

To investigate the effect of oral isotretinoin therapy on central macular thickness (CMT) thickness and choroidal thickness (CT) using optical coherence tomography (OCT).

METHODS

CT and CMT thickness of 43 eyes were evaluated at baseline, the third, and sixth month of isotretinoin therapy by spectral-domain OCT. For assessment of CT, OCT measurements were obtained at the fovea with six additional measurements at adjacent locations (at 500-1000 µm temporal to the fovea and 500-1000 µm nasal to the fovea).

RESULTS

Forty-three eyes from 43 patients with acne vulgaris, including 33 females (76.7%), who had a mean age of 24.81 ± 6.60 years, completed the study. The mean CMT was 231.49 ± 19.52 at the baseline and significantly decreased to 229.0 ± 19.57 (p = 0.02) and 229.28 ± 18.83 after three and six months, respectively (p < 0.03). The change in the macular thicknesses measured at four quadrants and choroidal thicknesses were not statistically significant during the study (p > 0.05).

CONCLUSION

The result of our study demonstrated choroidal thickness change is not significant in patients with acne vulgaris after systemic isotretinoin therapy during six months of follow-up. The decreased CMT amount was 2.2 microns; even if statistically significant, this amount is clinically insignificant.

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.