A 50 y.o. male with a hx of ESRD on dialysis, ht, copd, and hep C presents with a rash
What is the differential?
Our patient had Sweet’s syndrome.
Sweet syndrome was first described in 1964 by Robert Sweet when he described 8 cases of skin eruptions similar to erythema multiforme, associated with fever. The lesions show dense dermal infiltration of mature neutrophils and often have heaped up margins.. It can affect the CNS, bones, eyes, ears, mouth kidneys and spleen as well as skin.
Sweet’s syndrome has been linked to hematological malignancies particularly myelodysplastic syndrome and AML.. Non-Hodgkin’s lymphoma, CLL and multiple myeloma have also been reported. Idiopathic cases have been reported after viral illnesses.
Our patient had the rare bullous form of Sweet’s syndrome. These patients often have a hematologic disease or are positive for antineutrophil cytoplasmic antibodies (ANCA). Sweet’s syndrome can be difficult to diagnose based on appearance. There was originally concern for monkey pox in this case.
monkey pox is also presents with fever and a rash. A biopsy would show mixed lymphocytes and neutrophils. A PCR would be positive.
CAUSES OF SWEET’S SYNDROME
Drugs- minocycline, ofloxacin, trimethoprim-sulfa, carbamazepine, antineoplastics , antipsychotic clozapine), contraceptives and Lasix. Granulocyte-colony stimulating factor is a frequent cause.
Hematologic causes- Sweet’s syndrome has been linked to hematological malignancies particularly myelodysplastic syndrome and AML. These two hematologic problems account for 80% of cases. Non-Hodgkin’s lymphoma, CLL and multiple myeloma have also been reported.
Oncologic causes-Solid tumors have also been reported to cause Sweet’s syndrome. Carcinomas of the genitourinary organs, breast and GI tract are most common. Cases associated with malignancy can be very aggressive and resemble pyoderma gangrenosum. They can be difficult to treat even with steroids.
pyoderma gangrenosum presents with necrotic lesions
Idiopathic- occurs in young women after a mild respiratory illness and may be linked to pregnancy, inflammatory bowel disease, infections or vaccinations.
All of these conditions have an autoimmune component . The clinical appearance of erythema multiforme, Sweet’s syndrome, monkey pox and pyoderma gangrenosum can be similar. Usually pyoderma presents with necrotic lesions; often in patients with inflammatory bowel disease.
erythema nodosum presents with a lymphocytic infiltrate on biopsy Mycoplasma and herpes often cause it.
A biopsy is helpful in differentiating the lesions. There is a lymphocytic rather than neutrophilic infiltrate in erythema multiforme. There is no evidence of vasculitis in erythema multiforme, Sweet’s or pyoderma. Monkey pox is identified with a PCR.
CLINICAL PEARL
The treatment for Sweet’s syndrome is steroids not antibiotics.
Our patient was treated with steroids ( 1 mg/kg) and his lesions regressed. He was not found to have an associated malignancy but was found to have active Hep C with a positive fibro test acti; a test indicating active inflammation in the liver. He will be treated for this as an outpatient.
Snyder R, Libby T, Raciti P, et al. Myelodysplastic syndrome and Sweet’s syndrome are associated with a mutationin isocitrate dehydrogenase 1.. 2018 Anticancer Res. Apr;38(4):2201-2205.
Ferea C, Mihai S, Balan G, et al. Sweet syndrome associated with myelodysplastic syndrome—a review of a multidisciplinary approach. Life(Basel) 2023 Mar;13(3):809.
Maller B, Bigness A, Molino D, et al. Sweet’s syndrome associated with hematological malignancies. Leuk Res 2020;99:106461. Doi:10.1016/l.leukres.2020.106461.
Sherban A, Fuller C, Sethi M, et al. Bullous hemorrhagic Sweet syndrome with crytococcoid neutrophils in patients positive for antineutrophil cytoplasmic antibody without primary vasculitis. 2020 JAAD Cas Rep Dec;6(112):1196-1200.
The Primary Care Dermatology Society PO box 789 rickmansworth, WD3 ONY. UK https://www.pcds.org.uk/clinical-guidance/erythema-multiforme