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CASE REPORT
Year : 2022 | Volume
: 26
| Issue : 2 | Page : 86-88
Spotted fever rickettsioses should be considered in the differential diagnosis of “Fever with Purpuric Rash” in Saudi Arabia: A Case report
Ahmed H Nassar1, Abdullah S Abu-Aliat2, Salim Jamil3, Mohammed S Alshahrani2, Soha A Hawwam4, Esmat R Eid2
1 Department of Dermatology and Venereology, Tanta University, Tanta, Egypt; Department of Dermatology, The Armed Forces Hospitals-Southern Region, Khamis Mushait, Saudi Arabia
2 Department of Dermatology, The Armed Forces Hospitals-Southern Region, Khamis Mushait, Saudi Arabia
3 Department of Pathology, The Armed Forces Hospitals-Southern Region, Khamis Mushait, Saudi Arabia
4 Department of Dermatology and Venereology, Tanta University, Tanta, Egypt
Correspondence Address:
Dr. Soha A Hawwam
Department of Dermatology and Venereology, Faculty of Medicine, Tanta University Hospitals, El Geish Street, Tanta 31111
Egypt
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/jdds.jdds_99_20
There is a paucity of literature about human spotted fever rickettsioses (SFR) from the Arab Gulf Region, including Saudi Arabia. Here, we present an elderly Saudi man who had fever, headache, purpuric maculopapular skin rash, and an eschar. Together, the clinical findings, the serologic positivity, the presence of a vector tick in addition to the histopathologic changes, and the dramatic clinical response to oral doxycycline confirmed the diagnosis of SFR. This may be the first case of SFR reported to the health-care authorities in Saudi Arabia. We recommend considering SFR in the differential diagnosis of “fever with purpuric rash” in Saudi Arabia. Ideally, treatment with a tetracycline antibiotic should be considered for patients with fever and headache even before a purpuric rash develops.
Keywords: Purpuric rash, rickettsioses, spotted fever
Spotted fever rickettsioses (SFR) are global infections caused by Rickettsiae (R.), which are obligate intracellular small (0.3–0.5 mm × 0.8–2.0 mm) Gram-negative bacilli transmitted by bites of ticks, mites, fleas, or lice.[1] They begin with fever followed 3–5 days later by skin rash and probably an eschar at the bite site with/without lymphadenopathy. The diagnosis depends on the clinical data, exposure to a potential vector, and laboratory confirmation. Treatment with oral doxycycline must start once the disease is suspected to avoid serious complications.[1],[2] Hereinafter, we report a case of SFR from Saudi Arabia.
Case ReportIn April 2019, a 59-year-old Saudi male presented to the emergency department with fever, headache, and skin rash. He is a camel shepherd. Fever was followed shortly by skin rash and did not respond to medications prescribed in another hospital. He had diabetes, was on insulin, and had no history of traveling abroad. He used to remove qerdan/qorad, an Arabic word that corresponds to “ticks” in English, from his camels' skin. He sent us a video showing them.
On examination, except for fever (38.5°C) and rash, he was generally well. A widespread purpuric maculopapular rash, sparing the face and mucous membranes, was present [Figure 1]a, [Figure 1]b, [Figure 1]c and was nonblanchable on dermoscopic diascopy [Figure 1]d. A painless eschar was seen on his back [Figure 1]e, but he denied any arthropod bite. The preliminary diagnosis was a SFR. The differential diagnosis included viral infection and small vessel vasculitis.
Figure 1: (a-c) Widespread purpuric maculopapular rash, sparing the face and mucous membranes; (d) Nonblanchable on dermoscopic diascopy; (e) a painless eschar on his back; (f) The collected ticksComplete blood count revealed normal leukocytic count with neutrophil leukocytosis (8.01%, reference range “[RR]”: 2%–7.7%) and lymphopenia (0.73%, RR: 1.5%–4%). Liver and renal function tests and coagulation profile parameters were unremarkable. Serum electrolytes were normal except for hyponatremia (128 mmol/L; RR: 136–144 mmol/L). Serum albumin level was low (27 g/L; RR: 35–50 g/L), erythrocyte sedimentation rate was 62 mm/h (RR: 0–10 mm/h), C-reactive protein (CRP) level was 184.8 mg/L (RR: <10 mg/L), serum ferritin level was 746.8 μg/L (RR: 23.9–336.2 μg/L), fibrinogen level was 555 mg/dL (RR: 150–400 mg/dL), and Innovance® D-Dimer was 1.474 mg/I fibrinogen equivalent units (FEU) (RR: <0.35 mg/I FEU). Testing for antinuclear antibodies, syphilis, hepatitis B and C viruses, HIV, brucella, and malaria showed no abnormal data. Blood and urine cultures showed no growth and Gram stain of the sputum revealed few leukocytes along with normal respiratory flora. Using indirect immunofluorescence assay that utilizes inactivated R. Rickettsii and R. typhi, a serum sample collected 15 days after the start of fever, had high titers of R. rickettsii immunoglobulin G (IgG) (1:4096), and R. rickettsii IgM (1:128), R. typhi IgG (1:256), and R. typhi IgM (1:64) (Normal reference value for rickettsial antibodies is < 1:64). The radiologic imaging of the chest and abdomen was unremarkable.
The collected ticks were identified as unfed and blood-fed ticks of the genus Rhipicephalus (Rhipicephalus sanguineus) [Figure 1]f. The eschar biopsy demonstrated a wedge-shaped inflammation with coagulative necrosis and an overlying crust. Fibrin thrombi with disrupted endothelium were seen in small blood vessels [Figure 2]a, [Figure 2]b, [Figure 2]c, [Figure 2]d, [Figure 2]e. Intravenous ceftriaxone and oral azithromycin were empirically prescribed on admission with no improvement and thereby, were replaced by oral doxycycline 100 mg BID for 10 days with striking clinical improvement.
Figure 2: (a) Wedge-shaped inflammatory process, extending into the deep dermis beneath a crusted epidermis. (b) Crusting with necrotic cells and debris. (c) A fibrin thrombus in a small blood vessel with disrupted endothelium. (d) Dermal coagulative necrosis. (e) Deep dermal inflammation with necrosis, debris with adjacent capillaries showing endothelial proliferation, and reactive change Discussion Tick-borne viral, but not bacterial, diseases such as Alkhumra virus infection were recently reported in Saudi Arabia.[3] A serological surveillance study of R. conorii performed on volunteer school children (aged 8–16 years) from Dhofar Province (Oman Sultanate), a country at the southeastern border of Saudi Arabia, was positive in 58 ± 13 (mean ± standard deviation) of the sera tested in the six study localities. Together with the tick survey, transmission of such infection (R. conorii) does occur.[4] In addition, spotted fever group Rickettsia species was reported in Hyalomma dromedarii ticks in the United Arab Emirates, a country at the east border of Saudi Arabia.[5]
Our patient suffered the infection during April, the month during which ticks often start a high level of activity that continues to September; this season accounts for 90% of cases.[2] History of exposure to camels with ticks in their fur together with the presence of fever, headache, purpuric maculopapular skin rash, and a painless eschar suggested the diagnosis of SFR. The noticeable changes in the levels of acute phase reactants indicated an acute systemic inflammatory response. Rickettsioses are favored over viral infections when CRP levels exceed 100 mg/L, as in our patient. Viral infections generally have CRP levels under 50 mg/L.[6] Our patient had hyponatremia, a finding that occurs at the height of rickettsial infection in up to 50% of cases.[7]
The high titer of rickettsial antibodies supported the presumptive diagnosis of SFR caused by R. rickettsii. The low-level positive serology for R. typhi was explained by the cross-reactivity of the antibodies to R. rickettsii antigens with those of R. typhi, a member of the typhus group of rickettsioses.[8] Unfortunately, we could not perform polymerase chain reaction to identify the Rickettsia species precisely. The histopathologic findings of the eschar biopsy supported an arthropod bite reaction. Rhipicephalus sanguineus tick has been incriminated in transmitting R. rickettsii to humans in rural Arizona, USA[9] and may have transmitted the same organism to our patient. The striking response to oral doxycycline may aid the diagnosis of SFR.[2] Together, the clinical findings, the serologic positivity, the presence of a tick vector in addition to the histopathologic changes, and the rapid and complete clinical response to oral doxycycline support the diagnosis of SFR.
We reported this case to the local office of the Department of Infectious Diseases and Preventive Medicine, the Ministry of Health, Saudi Arabia in May 2019. In August 2019,[10] SFR with acute meningitis due to R. rickettsii was reported in a 15-year-old Saudi male from Riyadh Province, Saudi Arabia. The two reported Saudi patients with SFR were from Riyadh Province and had contact with camels. Further clinical and serological surveillance is required to detect the presence of SFR in different areas of Saudi Arabia and the Arab Gulf Region, especially among camel shepherds.
There may be underdiagnosis and/or underappreciation of rickettsial infections among humans in the Arab Gulf Region. Therefore, we recommend considering SFR in the differential diagnosis of “fever with purpuric rash” in Saudi Arabia.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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