Today’s Cox’s Conference is brought to you by expert discussant Dr. Arturo Dominguez who invited two dermatology residents to present us two interesting dermatology cases of adult-onset Still’s disease and of leukocytoclastic vasculitis in the setting of IgA-dominant post-infectious glomerulonephritis.
Adult-Onset Still’s Disease:
Adult-onset Still’s disease is an inflammatory condition characterized by an evanescent, salmon-colored rash, quotidian fevers, leukocytosis and arthralgias. Its etiology is unknown. It is a rare disease occurring in 0.16 to 0.62 per 100,000 people. Median age of diagnosis is 36 years but cases of age of onset up to the 80s have been described.
–Fever: nearly always present (85-100%). Quotidian or twice-daily. Usually in the PM and first sign of disease
–Rash: occurs in 62-77% of patients. Evanescent rash that occurs during fever spikes. Macular and papular. Salmon-colored and usually on the trunk
–Leukocytosis: Present in 72-91%. PMN predominant.
–Arthralgias: With or without synovitis. Occurs in 72-95% of patients. Usually in wrist, knees, and ankles.
–Elevated acute-phase reactants: elevated ESR, CRP, white count, and hyperferritinemia (69-97% of patients)
-Other findings that may be found include: myalgia, sore throat, hepatomegaly, splenomegaly, lymphadenopathy, serositis, abdominal pain, elevated LFTs, anemia, negative AMA, negative RF
Adult-onset Still’s disease is one of exclusion. The broad differential diagnosis includes infectious diseases (acute HIV, viral hepatitis, parvovirus B19, bacteremia, infective endocarditis, syphilis), malignancy (lymphoma, cutaneous T cell lymphoma, Castleman’s disease, leukemia), autoimmune/inflammatory disease (SLE, RA, reactive arthritis, dermatomyositis, vasculitis), drug reactions, Sweet syndrome, sarcoidosis, familial Mediterranean fever and HLH) .
There are several sets of diagnostic criteria but one widely used set is the Yamaguchi criteria. It has a four major criteria and give minor criteria. Adult-onset Still’s is diagnosed in the presence of 4 major criteria or 3 major + 2 minor criteria (79.2% sensitive and 93.8% specific).
- fever greater than or equal to 39 degrees C >= 1 week
- arthralgias >= 2 weeks
- non-pruritic, maculopapular, and salmon-colored rash distributed along trunks and extremities worsened during fevers
- leukocytosis with at least 80% granulocytes
- sore throat
- hepatomegaly or splenomegaly
- abnormal LFTs
- negative ANA and RF
Leukocytoclastic vasculitis is a microscopic pathologic description characterized by neutrophilic small vessel vasculitis. This requires 2 our of the 3 findings in small vessels:
- angiocentric or angioinvasive inflammatory infiltrates
- disruption of vessel walls by inflammatory infiltrate
- fibrinoid necrosis.
Cutaneous clinical findings of leukocytoclastic vasculitis include petechiae (nonblanching), palpable purpura, hemorrhagic bullae, subcutaneous nodules, livedo reticularis, ulceration, and urticaria.
Causes of leukocytoclastic vasculitis include:
- polyarteritis nodosa
- granulomatosis with polyangitis
- eosinophilic granulomatosis with polyangitis
- microscopic polyangitis
- Henloch-Shonlein purpura (IgA vasculitis)
- cryoglobulinemic vasculitis
- septic/infection-induced vasculitis
- Behcet’s disease
- urticarial vasculitis
- cutaneous polyarteritis nodosa
- hypersensitivity vasculitis
- drug-induced vasculitis
- paraneoplastic vasculitis