There is consensus among experts for use of the Strasbourg criteria, which have a definite and a probable diagnosis category and can direct management.
Various treatments have been tried with variable results. Successful treatment with anakinra, an IL-1 receptor antagonist, has been documented in case reports.
D47.2 – Monoclonal gammopathy
402415001 – Schnitzler syndrome
- Adult-onset Still disease (AOSD) – Both Schnitzler syndrome and AOSD are characterized by urticarial rash, fever, joint pain, and leukocytosis. Distinguishing features of AOSD include elevated ferritin levels, increased transaminases, and pharyngitis.
- Rheumatoid arthritis – Positive anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor; elevated inflammatory markers erythrocyte sedimentation rate and C-reactive protein (CRP); synovitis on exam with pain, swelling, and warmth of small joints of the fingers, wrists, and ankles; morning stiffness lasting more than 1 hour that improves with activity.
- Cryopyrin-associated periodic syndrome – Rare genetic disease involving the cryopyrin protein. Muckle-Wells syndrome presents with fever, hive-like rash, red eyes, joint pain, and severe headaches with vomiting; deafness / age-related hearing loss can develop. Episodes typically last 1-3 days. Familial cold autoinflammatory syndrome is triggered by exposure to cold or other environmental factors; it presents with a hive-like rash, fever, chills, nausea, headaches, and joint pain. Episodes typically last 1 day.
- Urticarial vasculitis – Presents similarly to Schnitzler syndrome with rash, fever, and joint pain. Decreased levels of complement as a result of increased consumption and anti-C1q antibodies are present in urticarial vasculitis but not in Schnitzler syndrome. Unlike true vasculitides, skin biopsy in Schnitzler syndrome will not show fibrinoid necrosis.
- Cryoglobulinemic vasculitis – Low complement values and presence of cryoglobulins causing systemic effects such as skin and renal disease; associated with hepatitis C, malignancy, or autoimmune condition; three different types, if polyclonal associated with Meltzer triad of palpable purpura, arthralgias, and myalgias.
- Systemic lupus erythematosus – SOAP BRAIN MD mnemonic (serositis, oral ulcers, arthritis, photosensitivity, blood disorders, renal involvement, antinuclear antibodies, immunologic phenomena, neurologic disorder, malar rash, discoid rash); must fulfill 4 of 11 of criteria according to the American College of Rheumatology.
- Chronic idiopathic urticaria
- Monoclonal gammopathy of undetermined significance (MGUS) – Clinically does not cause signs or symptoms; usually affects the elderly with peak age older than 85 years.