One case of acute febrile neutrophilic dermatosis

We report a case of acute febrile neutrophilic dermatosis. A 78-year-old woman had a one-week history of painful rash on the right lower leg. Dermatological examination revealed a round red, edematous erythema with unclear boundaries, sized 14 cm×14 cm, on the right posterior lower leg. The affected area was warm and tender with a few small pustules, some of which had merged and dried up. Cutaneous infiltration could be felt by palpation. Histopathological changes included thickening of the epidermal spinous layer, inflammatory infiltration, dilation of dermal blood vessels, extravasation of erythrocytes, and diffused perivascular infiltration of neutrophils, with few lymphocytes, eosinophils, as well as nuclear dust. A diagnosis of acute febrile neutrophilic dermatosis was made. Patient was initially treated with intramuscular injection of 1 mL of compound betamethasone, and oral triamcinolone tablets at a dose of 20 mg/qd was started on the next day. After 9 days of systemic treatment with glucocorticoids, the patient's condition was improved, and the patient was discharged. The patient continued to take oral triamcinolone tablets 16 mg/qd, with a weekly reduction of 4 mg until discontinuation. During a one-year telephone follow-up, there was no recurrence. So far, the patient is still under follow-up.