A 69-year-old man with ulcerative colitis presented with fever, fatigue, and rash. The patient reported onset of symptoms within 5 days of starting azathioprine. Physical examination revealed a fever of 39.5°C and a painful rash of erythematous plaques with pustules on bilateral elbows and neck (Fig. 1) and scattered macules on bilateral palms. The white blood cell count was 8000/mm3 with 96% neutrophils; the erythrocyte sedimentation rate was 60 mm/h. Biopsy of the elbow lesion revealed a dense dermal neutrophilic infiltrate, lack of perivascular inflammation, and papillary dermal edema consistent with Sweet’s syndrome (Fig. 2). Symptoms and rash rapidly resolved after discontinuing azathioprine.
Figure 1.
Rash on elbow consisting of erythematous plaques with overlying pustules.
Figure 2.
Histopathology of skin biopsy showing dense infiltrate of neutrophils in the dermis (asterisks).
Sweet’s syndrome (acute febrile neutrophilic dermatosis) is an uncommon inflammatory disorder characterized by acute onset of fever and a rash consisting of tender erythematous plaques with occasional pustules, typically distributed over the upper body and extremities, with characteristic histopathologic findings.1 The syndrome most often occurs secondary to malignancy or autoimmune disease such as inflammatory bowel disease, but can be associated with pregnancy, preceding infection, or drug reaction. Here, the syndrome was thought to be secondary to azathioprine, given the temporal relationship between drug exposure and symptoms, with most azathioprine-associated cases occurring within a month after exposure.2 , 3
Acknowledgments
We thank Willis Bowman, MD, and Kanal Singh, MD, for review and discussion of the case.
Funding Sources
None
Conflict of Interest
The authors declare that they do not have a conflict of interest.
References
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