Diagnosis: Sweet’s syndrome
A skin biopsy revealed subepidermal bullae with marked dermal and mixed lymphocytic and neutrophilic infiltrate consistent with Sweet’s syndrome.
Sweet’s syndrome, also known as acute febrile neutrophilic dermatoses, is a condition that was originally described by Dr. Robert Sweet in 1964.1 The condition can be classified based on etiology as "classical" or idiopathic, malignancy-associated, or drug-induced.2 Classical Sweet’s syndrome typically affects women 30 to 50 years of age, but has been reported in men and women of all ages.3-5 More than 500 cases have been reported in the literature, but incidence and prevalence data are limited.6 Conditions associated with classical Sweet’s syndrome include upper respiratory infection, gastrointestinal infection, inflammatory bowel disease, and pregnancy.5
Cellulitis and lupus erythematosus are part of the differential
The differential diagnosis for erythematous, indurated, tender skin and soft tissue lesions includes cellulitis, erysipelas, thrombophlebitis, urticaria, shingles, drug-induced eruptions, and herpes simplex virus infections.4-6
Less common conditions include erythema multiforme, erythema nodusum, tuberculosis, leukemia cutis, lupus erythematosus, vasculitis, pyoderma gangrenosa, Behçet’s disease, erythema elevatum diutinum, familial Mediterranean fever, and Sweet’s syndrome.4-6