Contents
Definition
Sweet's syndrome is an inflammatory disease with an abrupt onset. Fever attacks and attacks on the skin, eyes, muscles, joints and organs are typical. Sweet's syndrome is related to other neutrophilic dermatoses such as pyoderma gangrenosum (skin), neutrophilic hidradenitis (sweat glands), and Behçet's disease (sore mouth and weird). Sweet's syndrome can be triggered by cancer, but also by drugs or without a known underlying cause (reference: Vashisht P, 2021). The condition was described in 1964 by RD Sweet (reference: Sweet RD, 1964).
Occurrence
Sweet's syndrome is rare, but most common among middle-aged women, 30-60 years. Women: men: 4:1. It has also been described in children (reference: Vashisht P, 2021).
Symptoms

- Abrupt onset with fever and rash is typical.
- The rash appears suddenly and consists of tender nodules (papules) or hard spots (plaques) that go deep.
- Some also get sore eyes and mouth ulcers, joint and head pain.
- Symptoms from internal organs are less common
Disposing conditions
Respiratory tract infection, vaccination, chronic intestinal disease (IBD (Ulcerative colitis or Crohn's disease)), arthritis/Rheumatoid arthritis, blood diseases, incl Leukemia: Most often acute myelogenous leukemia. Other cancers are most often detected in the bowel, urinary tract or breasts. Pregnancy can also predispose.
Examinations

Medical history maps predisposing conditions and current symptoms (see above). Weight loss and general symptoms are requested.
Clinical the skin manifestations which consist of blisters (pustules, bullae), wounds (ulcerations) which may discolour in the center are examined. Can sometimes resemble pyoderma gangrenosum. The localization is most often on the upper side of the hands, but the face, neck, chest, back and legs can also be attacked. The rash increases in size and lasts for several weeks. Like Behcet's syndrome may not be pathergy test knock out.
Fever is present in 80-90%, especially where drugs are the trigger. Fatigue and headache are other common symptoms. Rheumatic joint pain or joint inflammation (arthritis) is seen in 20-60%. Muscle pain also occurs.
The eye can be attacked in the form of superficial inflammation (conjunctivitis), less often deeper inflammation such as episcleritis, scleritis, keratitis and uveitis (reference: Gottlieb CC, 2008).

Blood tests. Routine tests may include CRP, SR, hgb, white blood cells with differential count, platelets, electrolytes, liver, kidney and thyroid function tests, CK, protein electrophoresis and urine dipstick. Blood lowering reaction (SR) and CRP are elevated (systemic inflammation). Increased number of white blood cells (neutrophil leukocytosis). Pregnancy test in case of possible pregnancy.
No special rheumatism tests/antibodies are expected to turn out, but anti-CCP, ANCA, ANA, anti-DNA and antiphospholipid antibody can be taken to rule out similar conditions (see below).
Imaging. Considering cancer located in the buttocks, an indication for CT of the lungs, stomach area (abdomen) and pelvis, as well as mammography, possibly PET / CT.
Colonoscopy if necessary to rule out colon cancer.
Tissue sample (biopsy). Skin biopsy: shows in depth many neutrophil granulocytes which are a type of white blood cells (neutrophil dermatosis) and destroyed cells (leukocytoclastic), as well as edematous endothelial cells in blood vessel walls (vasculitis).
Diagnosis
Most often, the diagnosis is made on the basis of medical history, clinical examination and, not least, the tissue sample in the absence of similar conditions. Diagnostic criteria have also been developed (see ev Grans Compendium in Rheumatology).
Course of disease
One or more red and tender lumps in or under the skin that increase in size and last for several weeks. Skin changes may also have blisters (pustules), ulcers (ulcerations) and may fade in the center. Can sometimes look like pyoderma gangrenosum
similar diseases / differential diagnoses
- Allergic contact dermatitis
- Behcet's disease
- Dermatomyositis
- DRESS syndrome and other skin reactions to medications
- Infection / sepsis / erysipelas
- Endocarditis (infection)
- Herpes simplex
- Herpes zoster
- Leukocytoclastic vasculitis
- Leukemia cutis
- Lymphoma
- Mycobacterium marinum (Skin, joints, fever)
- PAN (Polyarteritis nodosum)
- Panniculitis
- Pyoderma gangrenosum
- Roseacea
- Serum sickness / hypersensitivity syndrome
- Fungal infection, Systemic mycosis
- Systemic lupus (SLE)
- Tuberculosis (Tbc)
- VEXAS syndrome
Treatment
Steroids (Prednisone) is used first. Local corticosteroid injections may also be considered. If insufficient effect and recurrent lesions are used potassium iodide or Colchicine. Alternatives are ciclosporin, methotrexate IVIG, rituximab, or vedolizumab (Entyvio) (reference: Vashisht P, 2021). NSAIDs can relieve symptoms.
Prognosis
The skin symptoms return spontaneously after 4-8 weeks, but may return. About 15-20% develop cancer.