Updated on 22/09/2017.
Sometimes, Sweet’s syndrome can occur in an unusual form. This is known as a disease variant.
Necrotizing Sweet’s syndrome.
Necrotizing Sweet’s syndrome is a rare variant of Sweet’s syndrome that mimics necrotizing fasciitis.
What is necrotizing fasciitis?
Necrotizing fasciitis (NF) is a rare and serious bacterial infection that affects the superficial fascia – a layer of connective tissue that lies beneath the skin and between the muscles and organs in the body. NF not only causes inflammation and damage to the fascia, but also the tissues next to it. Toxins made by the bacteria then destroy soft-tissue, causing it to die. This is known as soft-tissue necrosis.
What is necrotizing Sweet’s syndrome?
Necrotizing Sweet’s syndrome is an acute necrotizing form of neutrophilic dermatosis that not only causes skin lesions, the most common symptom of Sweet’s syndrome, but also affects the deeper tissues, and causes soft-tissue necrosis.
How many people have developed necrotizing Sweet’s syndrome?
By September 2017, at least seven cases of necrotizing Sweet’s syndrome had been reported in medical literature.
- In three patients with very weakened immune systems (Kroshinsky et al, 2012).
- In a 73-year-old male with chronic myelogenous leukaemia (Nakanishi and Kinjo, 2016).
- In a 24-year-old transsexual male with recurrent myonecrosis of the neck and upper chest (Otero et al, 2017).
- In a patient where the necrotizing Sweet’s syndrome was initially mistaken for NF (Kim et al, 2017).
- In a patient after elective hand surgery (Lipof et al , 2017).
How is it diagnosed?
Necrotizing Sweet’s syndrome is mainly diagnosed via biopsy. Tissue samples show white blood cells called neutrophils in the deep tissues, but unlike in Sweet’s syndrome, soft-tissue necrosis also occurs. Read more here.
How is it treated?
The treatment for necrotizing Sweet’s syndrome and NF is very different, so it’s important that the two conditions are not confused.
The main form of treatment for necrotizing Sweet’s syndrome is high-dose steroids, whereas NF is treated with antibiotics and wound debridement (surgical removal of the infected tissue). Antibiotics do not work in the treatment of necrotizing Sweet’s syndrome, and wound debridement must be avoided as it can lead to the development of new lesions. Read more here.
Can patients with Sweet’s syndrome, but not necrotizing Sweet’s syndrome, sometimes develop symptoms that mimic necrotizing fasciitis?
Yes. Paraneoplastic fasciitis can be a symptom of Sweet’s syndrome, and is sometimes confused with NF (Chaudhry et al, 2015: 128-129).
What is paraneoplastic fasciitis?
Paraneoplastic fasciitis is a type of fasciitis that develops alongside cancer. It causes inflammation and thickening of the fascia, but unlike in NF, soft-tissue necrosis does not occur. In patients with Sweet’s syndrome who develop paraneoplastic fasciitis, skin lesions are normally present, but not always.
On occasion, inflammation of the fascia can be a symptom of Sweet’s syndrome, even when someone does not have cancer.
Kim, B., Chun, D., Jeen, Y. and Kim, H. (2017) Necrotizing Sweet’s syndrome presenting as necrotizing fasciitis with a good response to immune suppressant treatment. International Journal of Rheumatic Diseases, Aug 16 (PubMed).
Kroshinsky, D., Alloo, A., Rothschild, B., Cummins, J., Tan, J., Montecino, R., Hoang, M., Duncan, L., Mihm, M. and Sepehr, A. (2012) Necrotizing Sweet syndrome: a new variant of neutrophilic dermatosis mimicking necrotizing fasciitis, Journal of the American Academy of Dermatology, Nov;67(5):945-54 (PubMed).
Lipof, J., Beck, L., Reddy, S., Southgate, R., Carney-Young, K. and Hammert, W. (2017) Necrotizing Sweet Syndrome of the Upper Extremity After Elective Hand Surgery. The Journal of Hand Surgery, Aug 19 (American Society for Surgery of the Hand).
Nakanishi, K. and Kinjo, M. (2016) Mimicker of necrotising fasciitis with systemic inflammatory response syndrome: recurrent necrotising Sweet’s syndrome associated with chronic myelogenous leukaemia. BMJ Case Reports, Mar 31 (PubMed).
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