Rheumatology Unit, Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
Correspondence to: S. S. Yeap. E-mail: yeapss{at}myjaring.net
SIR, We read with interest the letter by Hoi and Morand on the use of intravenous (i.v.) cyclophosphamide in the treatment of mononeuritis associated with ChurgStrauss syndrome (CSS). We agree with them that the presence of mononeuritis multiplex is a serious complication of CSS and warrants more aggressive therapy [1]. We wish to report two further cases of CSS, in Asians, presenting with mononeuritis multiplex. Both patients responded well to monthly pulses of i.v. cyclophosphamide with significant improvement of their neurological signs.
The first patient was a 38-yr-old Indian lady with a 2-yr history of bronchial asthma. She was treated with an inhaled ß2 agonist and inhaled corticosteroid. She presented with a 3-month history of low-grade fever, generalized malaise and symmetrical polyarthralgia. She developed progressive paraesthesiae and weakness affecting all four extremities 2 months after the onset of constitutional symptoms.
On presentation, the patient had bilateral wrist and foot drop and loss of pinprick sensation in a glove and stocking distribution. There were generalized rhonchi on auscultation of her chest. There were multiple purpuric rashes and non-healing ulcers on the dorsum of both feet. Her investigation results are summarized in Table 1. The diagnosis of CSS was made in accordance with the American College of Rheumatology classification criteria [2].
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The second case was a 68-yr-old Chinese man who had had chronic bronchial asthma and allergic rhinitis since childhood and had a 10-yr history of chronic rhinosinusitis. The patient was diagnosed as having pulmonary tuberculosis in June 2001 and was treated with the standard four-drug regime, consisting of streptomycin, isoniazid, rifampin and pyrazinamide with pyridoxine supplementation. He was on low-dose prednisolone daily for control of his bronchial asthma. The patient presented in August 2002 with a 2-week history of progressive bilateral lower limb weakness and paraesthesiae, low-grade fever and arthralgia. On examination, he had complete bilateral foot drop, loss of pinprick sensation over the sole and dorsum of both feet and lateral aspects of both calves, consistent with the L5 and S1 dermatomes, and loss of proprioception in both feet. His investigation results are summarized in Table 1.
CSS was diagnosed in the absence of other causes of hypereosinophilia. The patient was treated with the same regime as in case 1, with additional i.v. methylprednisolone 500 mg on each pulse of i.v. cyclophosphamide (0.75 g/m2, to a maximum of 1 g). He completed 6 months of anti-tuberculous treatment and subsequently had isoniazid and pyridoxine prophylaxis until he finished the six i.v. cyclophosphamide pulses. The hypereosinophilia and elevated inflammatory markers resolved within days, with progressive improvement of his neurological deficits. At the 6th month of treatment, the symmetrical distal sensorimotor neuropathy had almost completely resolved. However, his bronchial asthma required prednisolone 7.5 mg daily for symptomatic control.
Peripheral neurological involvement has been found in up to 75% of cases of CSS [36]. The pattern of neurological involvement may be that of mononeuritis multiplex, symmetrical or asymmetrical polyneuropathy. It can result in long-term disability. Corticosteroids are the first-line recommended treatment for CSS [7] and adjuvant immunosuppressants are used for severe disease [8]. Both our patients were considered to have severe disease and were thus started on combination therapy immediately. Intravenous cyclophosphamide was preferred as it has been shown to cause fewer adverse effects than oral cyclophosphamide [9]. In case 1, in addition to her mononeuritis, the patient also had vasculitic leg ulcers, which we felt warranted additional i.v. cyclophosphamide therapy. In case 2, i.v. cyclophosphamide was added to the treatment regime because of the rapid rate of progression of disease from the onset (2 weeks), and also because he was already on oral corticosteroids for his bronchial asthma. Both our cases demonstrated significant clinical and functional improvement with combination treatment within 6 months. Whether they would have improved so rapidly without i.v. cyclophosphamide is unknown, but a previous study showed that the mean time to clinical remission in CSS patients is 14 months [3].
Our two cases support the observation by Hoi and Morand [1] that the addition of i.v. cyclophosphamide to i.v. corticosteroids is an effective treatment for mononeuritis in CSS and can be also effective in Asian populations. However, a prospective trial would be required to fully evaluate the effectiveness and riskbenefit ratio of this particular therapeutic regimen.
The authors have declared no conflicts of interest.
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