Background: The simultaneous occurrence of Sweet's syndrome (SS) and erythe
ma nodosum (EN) in 1 patient is rare. Our review of the literature revealed
only II biopsy-proved cases in which the 2 reactive dermatoses occurred to
gether. None were associated with an underlying malignant neoplasm.
Observations: We report a biopsy-proved case of SS and EN occurring simulta
neously in a patient with an underlying malignant neoplasm (specifically, a
cute myelogenous leukemia). We also report another biopsy-proved case of SS
and EN occurring simultaneously in a patient with underlying Crohn's disea
se.
Conclusions: The simultaneous occurrence of SS and EN in 1 patient is rarel
y reported. Both disorders are reactive dermatoses that share many overlapp
ing features. Although individually distinctive, SS and EN are also part of
a growing continuum of reactive dermatoses. Our expanded understanding of
the similarities and simultaneous manifestation of SS and EN may help us in
the future to identify a common underlying mechanism of pathogenesis.