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COMPLETE CLINICAL DETAILS FOR ANTHRAX CASE 8 |
Last Updated 06 Nov 2002 |
Source: Freedman A et al. Cutaneous Anthrax associated with microangiopathic hemolytic anemia and coagulopathy in a 7-month-old infant. JAMA 287(7), 869-874, 2002 (Feb. 20, 2002). October 1, 2001 A 7-month-old, previously healthy, white male infant was admitted to the hospital on October 1, 2001. Two days prior to admission (September 29, 2001) he was noted to have a painless red macule on the proximal medial aspect of the left upper extremity with associated swelling. During the next 24 hours, the arm became increasingly edematous, the macule evolved to a papule, and a slight serous drainage began. However, the patient remained afebrile and without apparent pain or other systemic symptoms. His primary pediatricians treated him with amoxicillin/clavulanate potassium for presumed cellulitis, but he required admission to the hospital after the third dose, due to increased swelling and drainage of the lesion, and his difficulty in tolerating oral medication. The infant did not have a significant medical history but he had recently played outdoors in a New York park and had also visited his mother at her workplace, the offices of a national television news organization, for an hour the day before his symptoms began. Anthrax spores were subsequently found at his mother's workplace. On admission, the infant was alert, afebrile, and in no apparent distress. Laboratory studies revealed significant leukocytosis and hyponatremia (click for daily Table). Blood was not sent for culture, but intravenous ampicillin/sulbactam was initiated. Surgical incision and drainage performed under local anesthesia revealed no underlying abscess, but dark red fluid was expressed from the lesion. Bacterial cultures were not performed. October 2, 2001 On hospital day 2, the left arm showed massive, nonpitting, nontender edema with a dark red macule approximately 2 to 3 cm in diameter. There was copious, yellow serous drainage from the wound and paler erythema extending across the anterior thorax to the sternum. No axillary adenopathy was palpable. The hyponatremia was managed with fluid restriction and clindamycin was added to the antibiotic regimen. An infectious disease consultation was obtained. A gram stain of the wound drainage showed neither white blood cells nor organisms. Differential diagnoses considered were infection of bone, soft tissue, or both; arachnid bite; and obstructive mass lesion. Ultrasound of the left upper extremity revealed diffuse inflammation without abscess, and minimal axillary lymphadenopathy. Doppler studies excluded deep vein thrombosis or other vascular compromise to the limb. Later that day, the patient became febrile (39.2°C) and developed significant thrombocytopenia. During the next 2 days, the arm edema decreased slightly, a 3-mm area of central necrosis was noted at the wound site, and petechiae appeared on the left anterosuperior thorax and axilla. The patient's hematocrit decreased to 23.3%, and low-grade fever, hyponatremia, thrombocytopenia, and leukocytosis persisted, now with a significant number of band forms. Due to loss of intravenous access, the antibiotic regimen was changed to oral cephalexin and clindamycin. October 5, 2001 By hospital day 5, the fever resolved and the arm edema had decreased
considerably.
At this point, the working diagnosis was cutaneous and systemic loxoscelism, as the clinical course and the evolution of the skin lesion seemed more consistent with envenomation than an infectious process. Dermatologic consultation concurred with this diagnosis. Oral prednisolone was begun and antibiotics were discontinued. While the patient's arm edema improved and he remained afebrile, his
hematologic status worsened during the next few days. The hematocrit decreased
to 14.3% with accompanying tachycardia, necessitating 2 transfusions of 15 mL/kg
of packed red blood cells. Coagulopathy was evident, with ongoing
thrombocytopenia and elevated D-dimer levels and fibrin degradation products. A
persistent hypofibrinogenemia required transfusion of 4 U of cryoprecipitate.
Renal insufficiency, with elevated serum urea nitrogen, hematuria, proteinuria,
transient oliguria, and hypertension (systolic blood pressure of 130 mm Hg and
diastolic blood pressure of 85 mm Hg), were present.
October 12, 2001 That day, the first case of cutaneous anthrax in New York
(see
case 2) was reported and
the New York Department of Health was notified that this infant was potentially
infected with anthrax. Two skin biopsies of the lesion were performed the next
day, and these, as well as blood obtained on hospital day 2, were sent to the
Centers for Disease Control and Prevention for polymerase chain reaction
diagnosis and immunohistology, respectively. Two days later, these tests were
reported as positive for B anthracis, with significant anthrax DNA
present in the serum sample and immunohistochemical detection of fragmented
anthrax bacilli in the biopsy tissue.
October 18, 2001 On day 20 of the patient's illness, the IgM response decreased but the IgG
response intensified and extended to the edema and lethal factors band of 89 to
93 kd. The patient was discharged home on day 17 of illness
(October 15, 2001), receiving oral
ciprofloxacin, the treatment recommended by the Centers for Disease Control and
Prevention. His platelet count and fibrinogen level were normal, but evidence of
a mild hemolysis persisted. After 2 weeks of ciprofloxacin, when the other
anthrax isolates were shown to be susceptible to penicillin, amoxicillin was
used as the antibiotic.
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