Churg-Strauss Syndrome
Symptoms of Churg-Strauss Syndrome
Churg-Strauss Syndrome (CSS) is a systemic vasculitis. This disease was first described
in 1951 by Dr. Jacob Churg and Dr. Lotte Strauss as a syndrome consisting of “asthma,
eosinophilia [an excessive number of eosinophils in the blood], fever, and accompanying
vasculitis of various organ systems”. CSS shares many of the clinical and
pathological features of polyarteritis nodosa (“PAN”, another type of
vasculitis). Churg and Strauss discovered that the presence of granulomas as well as the
abundance of eosinophils distinguished this disease from PAN. Another name for
Churg-Strauss Syndrome is Allergic granulomatosis
Asthma is one of the cardinal features of CSS. Asthma symptoms may begin
long before the onset of vasculitis – e.g., many years before any other symptoms of
CSS arise, and long before the diagnosis of CSS is made. Other early symptoms/signs
include nasal polyps and allergic rhinitis.
The next phase of the disease is often marked by eosinophilia, the
finding of an excessive number of eosinophils in the blood or in tissues. An eosinophil is
one subtypes of white blood cell. Normally, eosinophils comprise 5% or less of the total
white blood cell count. In CSS, the percentage of eosinophils may reach as high as 60%. In
the picture below, the eosinophils are shown by the dark pink stain.
The third phase of the illness is a vasculitis, which involves the skin,
lungs, nerves, kidneys, and other organs. Particular mention should be made of the
frequent devastating involvement of the nerves (called mononeuritis multiplex), which
produces severe tingling, numbess, shooting pains, and severe muscle wasting/power loss in
the hands or feet. The list below contains the organs commonly involved by CSS and the
specific disease manifestation(s) in each organ.
nose
Sinusitis, including allergic rhinitis
Nasal polyps
Lung
Pulmonary infiltrates (only one-third of all patients)
Bleeding into the lungs (occasionally)
Diffuse interstitial lung disease (rarely)
Skin
Rashes
Palpable purpura
Nodules (above or below the skin), often at sites of pressure, such as the elbows
Kidney
Glomerulonephritis (inflammation in the small units of the kidney that filter blood)
Hypertension
Gastrointestinal
Lesions (vasculitic) are occasionally found in the GI tract
Granuloma sometimes found in spleen
Nerve
Peripheral nerve involvement including pain, numbness, or tingling in extremities
(neuropathy/mononeuritis multiplex)
Cause of Churg-Strauss Syndrome
The cause of CSS is unknown but is probably multi-factorial. Genetics may play a small
role in the disease, but CSS is almost never seen in two members of the same family.
Environmental factors such as exposure to industrial solvents may play a role in
susceptibility to this disease, but this is largely speculative. Infections may be the
inciting event(s), but to date there is no definitive evidence of this.
Diagnosis of Churg-Strauss
Syndrome
Among all of the vasculitides, asthma is a distinctive feature of CSS
alone. However, not all patients with asthma have vasculitis – only a tiny minority
do, in fact. It is the specific combination of symptoms and signs, the pattern of organ
involvement, and the presence of certain abnormal blood tests (eosinophilia, in
particular) that help the doctor make the diagnosis. In addition to a detailed history and
physical examination, blood tests, chest X-rays and other types of imaging studies, nerve
conduction tests, and tissue biopsies (e.g., of lung, skin, or nerve) may be performed to
help diagnose CSS.
The American College of Rheumatology (ACR) has established criteria that
must be fulfilled in order to classify a patient as having CSS. These criteria were
intended to distinguish CSS from other forms of vasculitis (for the purposes of research
studies). Not all patients meet every criterion. Some, in fact, may have only 2 or 3
criteria, yet their physicians are still comfortable classifying their disease as CSS. The
ACR selected 6 disease features (criteria) as being those that best distinguished CSS from
other vasculitides. In order to be classified as a CSS patient in a research study,
therefore, a patient should have at least 4 of the 6 ACR criteria.
These criteria include: 1) asthma; 2) eosinophilia [>10% on
differential WBC count]; 3) mononeuropathy; 4)
transient pulmonary infiltrates on chest X-rays; 5) paranasal sinus abnormalities; and 6)
biopsy containing a blood vessel with extravascular eosinophils.
Treatment of Churg-Strauss
Syndrome
CSS usually responds to prednisone. Initially, high doses of oral
prednisone are used in an attempt to get the disease into remission as quickly as possibly
(e.g., using oral prednisone 40-60 mg/day). After the first month or so, this high dose of
prednisone is gradually tapered down over the ensuing months. Other immunosuppressive
drugs, such as azathioprine, cellcept, methotrexate, or cyclophosphamide may be used in
addition to prednisone. High doses of intravenous steroids (usually methylprednisolone)
maybe useful for those patients with severe disease or for those who are unresponsive to
the combination of oral prednisone used with other immunosuppressive medications.
Prior to the advent of prednisone, CSS was often a fatal disease. The
majority of patients died from rampant, uncontrolled disease. With present therapy,
constitutional symptoms begin to resolve quite quickly, with gradual improvement in
cardiac and renal function, as well as improvement in the pain that results from
peripheral nerve involvement. The course of therapy can last for 1 to 2 years, although
the length and type of treatment depend on the severity of disease and the organs
involved. The patient’s response to treatment and the continuation of disease control
during lowering of the prednisone dose are the primary determinants of how long therapy is
continued. Laboratory monitoring of blood tests is very helpful in gauging the activity of
disease. Some of the most useful laboratory tests are the erythrocyte sedimentation rate
(ESR) and the eosinophil count. |
