Sweet Syndrome – 3 Interesting Facts
- Sweet syndrome (acute febrile neutrophilic dermatosis) is a neutrophilic condition that yields an urticaria-like reaction pattern.
- Oral prednisone, with an initial dose of 20 to 60 mg/day, tapering over 2 to 4 weeks, is the most commonly used treatment.
- In most cases, Sweet syndrome resolves over a period of weeks, without sequelae. Patients who do not respond to therapy or who have neutropenia should be evaluated for an underlying systemic disorder (e.g., myelogenous leukemia, connective tissue disorder, inflammatory bowel disease).
Etiology and Risk Factors
- Sweet syndrome may be precipitated by a variety of insults, including medications, underlying malignancy (myeloid and solid tumors), autoimmune disorders, inflammatory bowel disease, and infection.
- Typically, the condition affects young adults and geriatric patients; children are rarely affected.
- The condition is more common in women than men.
Drugs associated with Sweet Syndrome
| Drugs Frequently Implicated in Sweet Syndrome |
|---|
| Acyclovir |
| Granulocyte colony-stimulating factor (G-CSF) |
| Lenalidomide |
| Minocycline |
| Trimethoprim-sulfamethoxazole |
Diagnosis
Approach to Diagnosis
- Because the clinical findings are rather nonspecific, a biopsy is usually recommended.
Physical Examination
- Symptoms of an upper respiratory syndrome or malignancy are present in many patients.
- The primary lesion is a tender, round to oval, erythematous papule or plaque.
- The condition usually affects the distal extremities and acral areas.
- Some patients may demonstrate a pseudovesicular (juicy) edge, frank pustules, or even ulceration.
- Systemic findings include fever, malaise, arthralgias and/or arthritis, conjunctivitis, and oral lesions that resemble aphthous ulcers.
Laboratory Tests
- A CBC may demonstrate neutrophilia, and neutropenia in the setting of Sweet syndrome is more concerning for an associated lymphoid malignancy.
- Antibodies to neutrophil cytoplasmic antigens, antineutrophil cytoplasmic antibodies (ANCAs), are demonstrated in about 80% of cases, and the ESR can also be elevated.
Diagnostic Procedures
- A 3- or 4-mm punch biopsy is often suggestive or even diagnostic of the condition.
How is Sweet Syndrome treated?
Drug Therapy
- Oral prednisone, with an initial dose of 20 to 60 mg/day, tapering over 2 to 4 weeks, is the most commonly used treatment.
- Doxycycline or minocycline, 100 mg PO bid for 2 to 6 weeks, can also be used.
- Indomethacin, 100 to 150 mg/day for 1 to 3 weeks, can also be used.
- Colchicine and dapsone are alternatives that are used less often.
References
Rochet NM, Chavan RN, Cappel MA, Wada DA, Gibson LE. Sweet syndrome: clinical presentation, associations, and response to treatment in 77 patients. Journal of the American Academy of Dermatology. 2013;69(4);557-564. Reference
