Table 4.

Clinical criteria for the diagnosis of Schnitzler's disease [134]. A definite diagnosis is justified by the fulfillment of the 2 mandatory criteria and at least 2 or 3 minor criteria in patients with IgM or IgG monoclonal gammopathy, respectively. Diagnosis is probable when the 2 mandatory criteria are fulfilled and at least 1 or 2 minor criteria in patients with IgM or IgG monoclonal gammopathy, respectively, are present.

Mandatory criteria

(i) Chronic urticaria-like skin rash  (ii) IgM or IgG monoclonal gammopathy

Minor criteria

(i) Unexplained recurrent fever > 38°C  (ii) Abnormal bone remodeling assessed by bone scintigraphy or magnetic resonance imaging with abnormal bone alkaline phosphatase level  (iii) Neutrophilic dermal infiltrate at skin biopsy with neither fibrinoid necrosis nor significant dermal edema  (iv) Leukocytosis (neutrophils > 10, 000/mm3) and/or elevated C-reactive protein (>30 mg/l)