A pseudoleukemic blood differentiation in a 13-year-old child: an extraordinary presentation of Churg-Strauss syndrome
A 13-year-old girl presented at the pediatric department of a general hospital with malaise, dyspnea, diarrhea, and wasting. Three months earlier, she had been diagnosed with allergic asthma. Her previous medical history had been uneventful with no earlier signs of obstructive airway disease. The family history was unremarkable.\nTherapy for asthma had been started consisting of combined inhalation therapy with formoterole/budesonide. In the following months, she developed progressive fatigue, occasional nasal bleeding, painful swelling of the joints, small transient ulcerations of the skin, and tingling with a sensation of numbness of the right foot. Twice, she had been treated with a short course of prednisolone because an increase of respiratory distress was interpreted as an exacerbation of asthma, which resulted in a temporary relief. A few days prior to admission, the complaints had suddenly increased when she developed watery diarrhea.\nPhysical examination showed tachydyspnea with rales, mild expiratory wheezing, and dark purple lesions on the extremities. Both hands showed arthritis of the proximal interphalangeal joints with interdigital pustules on the right hand. There was a slight proptosis of the left eye.\nInitial laboratory studies revealed an ESR of 80 mm/h (reference range, 1–15 mm/h), a white blood cell count of 65.8 × 109/L (reference range, 4–14 × 109/L) with 14% neutrophils, 15% lymphocytes, 67% eosinophils (absolute count of 44 × 109/L), 6% monocytes, and 0% basophils. Urinalysis was normal with no signs of proteinuria.\nBecause of the extreme hypereosinophilia combined with numerous aspecific symptoms, an eosinophilic leukemia had to be excluded. The girl was immediately transferred to the pediatric oncology unit of an academic hospital where a bone marrow aspiration was performed next day. This showed, apart from many normal eosinophilic granulocytes, no abnormalities.\nChest radiography (Fig. ) showed interstitial and peribronchial infiltration; a computed tomography (CT) scan (Fig. ) of the thorax revealed bronchiectasis with mucus impaction and multiple granulomatous nodules. Electro- and echocardiogram and abdominal ultrasound revealed no abnormalities. An MRI and CT scan of the head showed a lesion in the left orbita. Neurological examination showed signs of mononeuritis of the left n. medialis. However, an EMG was normal.\nExtensive cultures and serologic tests were negative for infectious diseases caused by bacteria, viruses, parasites, or fungi. A biopsy of the nasal mucosa revealed eosinophilic vasculitis. A gastroduodenoscopy was not performed because of the high risk of perforation.\nBoth clinical symptoms and test results fitted with the diagnosis CSS. This diagnosis was confirmed when laboratory results showed a highly increased titer for ANCA with a perinuclear pattern at immunofluorescence (1:1280). An ELISA showed the presence of antibodies against MPO (1072 kAU/L, normal 0–15) with a negative ELISA for ANCA against proteinase 3 (PR3) and a highly elevated IgE (5035 kU/L, normal 0–100). Also, the rheumatoid factor as measured by ELISA was highly increased (2560 kU/L, normal 0–12.5) with negative anti-CCP, ANA, and anti-double stranded DNA.\nSubsequently, high-dose corticosteroid pulse therapy was started followed by oral prednisolone. The blood eosinophilic count dropped from a maximum of 51.6 × 109/L to 0.04 × 109/L, and all signs of the disease disappeared completely in a few days.\nThe patient was discharged from the hospital in an excellent condition. The patient is now in a good clinical condition with normal spirometric tests and a normal chest X-ray.