Skip to content

Spotted fever

Rickettsia rickettsiae

Rocky mountain spotted fever by (lxodes, dermacentor tick, Rhipicephalus sanguineus dog tick)

dog tick

  1. early symptoms similar to flu
  2. rash after 3 to 5 days start on wrist and ankles then to trunk due to small vessel vasculities
  3. Inoculation eschar may or may not present inoculation eschar of tick bite
  4. G-6-P patient are at severe risky

Cases

--- "Case 1" A 5-year-old female resident of Cape Girardeau County, Missouri, presented to an emergency department and was evaluated by one of us (S.J.W.) on June 1, 2001, with a 1-week history of intermittent fever, with temperatures as high as 40°C. Three days after the onset of fever, she developed a maculopapular erythematous rash on her extremities, including her palms and soles, that moved centripetally to involve her trunk. Her parents reported tick exposure around their rural residence, but no definite antecedent tick bite. The family did not own a dog. The patient's additional symptoms at presentation included mild nausea the previous week, headache, and a "scratchy" sore throat. Other than rash, the findings of the physical examination were unremarkable. The patient's temperature was 40.6°C. Significant laboratory results included a white blood cell count of 8800 × 103/µL, with 5% band cells, 70% neutrophils, 17% lymphocytes, and 8% monocytes. The platelet count was 192 × 103/µL. The serum glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels were elevated (60 µL and 80 µL, respectively). Serologic tests were negative for Ehrlichia chaffeensis. A 2-week course of oral doxycycline was prescribed.

The patient's fever abated on June 3, and she reported feeling much better the foling day. Her fading rash was still visible (Figure 2 and Figure 3). She had an increased appetite and, according to her mother, was again becoming playful. Serum samples collected on days 7 and 35 of the illness were tested with an indirect immunofluorescence assay, which demonstrated rising IgG antibody titers that were reactive with R rickettsii at dilutions of 1:32 and 1:2048, respectively).

--- "Case 2" 11-year-old white female resident of Cape Girardeau County presented in late May with a -grade fever at home (in-office temperature, 38.3°C), frontal headache, stomachache, and an erythematous maculopapular rash on her arms, legs, and trunk that had spread to her palms and soles. There were no oral lesions. The diagnosis of Coxsackievirus hand-foot-and-mouth disease was made, and the patient was sent home. Her fever, rash, and headache persisted. Two days later, nausea and vomiting developed. The patient was evaluated in the emergency department, diagnosed as having viral gastroenteritis, treated with intravenous fluids, and discharged with promethazine suppositories. Four days later, she was treated by a chiropractor for neck and back pain, without relief. The next day she was hospitalized for further evaluation and treatment. On admission, she had petechiae in some areas and blanching erythematous papules in others, but no palpable purpura. It was unclear when her rash had developed petechial characteristics. She was hemodynamically stable throughout her illness, and the headache, vomiting, fever (temperatures as high as 40°C), and rash were her predominant complaints. There was no recollection of a tick bite. The family did own a healthy dog. The patient denied photophobia on admission, but developed it later in the hospitalization. She had no meningismus. She had been treated for attention deficit disorder and gave a history of having had migrainelike headaches. A review of systems revealed no other abnormalities.

On admission, the patient underwent a spinal fluid examination (negative results) because of the fever, neck pain, vomiting, and petechial rash. A complete blood cell count demontrated a white blood cell count of 12 × 103/µL (5% band cells, 43% segmented neutrophils, 40% lymphocytes, 10% monocytes, and 1% reactive lymphocytes). The hemoglobin level was 12.1 g/dL, and the platelet count was 379 × 103/µL. A comprehensive metabolic profile showed a normal sodium level (138 mEq/L) and elevated levels of aspartate aminotransferase (51 U/L) and alanine aminotransferase (95 U/L). Other laboratory test results were normal. The leading diagnosis at this time was still a viral syndrome, and the patient was treated with ceftriaxone pending culture results.

Two days into her hospitalization, one of the authors (S.J.W.) was consulted, and a prophylactic regimen of doxycyline was initiated pending titer results. The patient's fever abated less than 2 days later, with resolution of her headache and vomiting. Two days later, she was discharged, with the rash beginning to fade on her extremities. At discharge, her RMSF IgG serology drawn during hospitalization was negative, with the IgM positive at >1:2048. She was treated with doxycycline for 14 days and had no reported sequelae.