A 55-year-old man presented to the emergency department with paresthesia, dysesthesia, and weakness that had persisted for one week. The symptoms were asymmetric and indicated dysfunction of multiple peripheral nerves. The patient reported a history of asthma that had worsened over the previous few months.
During the examination, a crimson, purpuric rash was noted on the posterior calves (see accompanying figure); the patient had not noticed the rash before. The lesions were minimally palpable, but not pruritic or painful, and they did not blanch. The patient had a white blood cell count of 15,600 cells per mm3 (15.6 × 109 per L) with 47 percent eosinophils.
The answer is A: Churg-Strauss syndrome. Churg-Strauss syndrome is a rare multisystem disorder characterized by small vessel vasculitis, prominent eosinophilia, and granulomatosis. The initial presentation varies based on which organ system is most prominently involved. Pulmonary and neurologic findings are most common (70 percent of cases).1 Integumentary, renal, gastrointestinal, cardiovascular, and musculoskeletal findings are also common.
Conditions associated with Churg-Strauss syndrome suggest that it is an autoimmune process (e.g., allergic symptoms, elevated eosinophil count, presence of humoral factors such as rheumatoid factor and antineutrophil cytoplasmic antibodies).
Eosinophilia (more than 10 percent)
Neuropathy, mononeuropathy, or polyneuropathy
Migratory or transient pulmonary opacities or infiltrates
Paranasal sinus abnormalities
Blood vessel biopsy showing extravascular eosinophil accumulation
Skin manifestations of Churg-Strauss syndrome include palpable purpura; a macular or papular erythematous rash; hemorrhages (petechiae to ecchymoses); and tender cutaneous or subcutaneous nodules, often from granulomas. These skin manifestations may be caused by vasculitis, eosinophil accumulation, or granulomatosis. Cardiovascular involvement (e.g., pericarditis, heart failure, infarction) can be life-threatening. Renal dysfunction is often present, most commonly in the form of segmental focal glomerulonephritis.
Corticosteroids are the mainstay of therapy for Churg-Strauss syndrome. Prednisone (1 mg per kg per day) is administered for four to 12 weeks or until symptoms have fully resolved, then the dosage is tapered.3,4 A short course (three days) of intravenous methylprednisolone (Solu-Medrol; 1 g per day) may be effective in the acute phase of the disease.3 Before the advent of steroids, Churg-Strauss syndrome was nearly always fatal; the five-year survival rate is now approximately 80 percent.5
Eosinophiliamyalgia syndrome causes an influenza-like illness with severe, incapacitating myalgia. However, muscle weakness usually does not occur until later in the disease. Eosinophiliamyalgia syndrome does not affect peripheral nerves.
Strongyloidiasis is an intestinal Strongyloides stercoralis infection, which may cause marked eosinophilia in the acute stage. The infection leads to nausea, vomiting, and diarrhea. A perianal rash (larva currens) may occur in the chronic stage. A rash involving the trunk and extremities usually affects only patients who are immunocompromised and have severe strongyloidiasis. Neuromuscular complications typically do not occur.
More than 90 percent of patients with Wegener's granulomatosis have upper or lower respiratory disease or both, including purulent sinus discharge, sinus pain, tracheal inflammation, and sclerosis. Wegener's granulomatosis causes vasculitis, but not eosinophilia.1
Wells' syndrome (eosinophilic cellulitis) is a pruritic rash that is limited to the skin. The rash is secondary to eosinophils invading the dermis and epidermis. Pruritus or a burning sensation often precedes the rash.
|Churg-Strauss syndrome||Small vessel vasculitis with eosinophilia, history of asthma, granulomatosis|
|Eosinophilia-myalgia syndrome||Influenza-like illness, severe myalgia with remarkable eosinophilia|
|Strongyloidiasis||Eosinophilia and rash without neuromuscular complications|
|Wegener's granulomatosis||Small and medium vessel vasculitis without eosinophilia|
|Wells' syndrome||Isolated eosinophil accumulation in the dermis and epidermis|