Tick Bite Fever
Description Diagnostic Criteria General and supportive measures Medicine Treatment Referral ICD-10 code: A79.9 DESCRIPTION A tick-borne febrile illness caused by Rickettsia conorii or africae . The rash appears on days 3–5 of the illness. It spreads from the extremities to the trunk, neck, face, palms, and soles within 36 hours. The lesions progress from macular to maculopapular and may per
General and supportive measures
ICD-10 code: A79.9
DESCRIPTION
A tick-borne febrile illness caused by Rickettsia conorii or africae.
The rash appears on days 3–5 of the illness. It spreads from the extremities to the trunk, neck, face, palms, and soles within 36 hours. The lesions progress from macular to maculopapular and may persist for 2– 3 weeks.
Atypical cutaneous findings may occur.
Complications include:
- vasculitis,
- encephalitis,
- thrombosis,
- renal failure,
- myocarditis,
- pneumonitis, and
- thrombocytopenia.
DIAGNOSTIC CRITERIA
The diagnosis is made on clinical grounds.
Clinical
- Fever, headache, malaise, myalgia and arthralgia.
- Maculopapular rash that may involve the palms and soles.
- Eschar at the site of the tick bite is associated with regional lymphadenopathy and splenomegaly.
Investigations
- Initiate treatment empirically.
- If diagnostic uncertainty: PCR on blood sample or on swab from base of eschar.
- Do not perform serology.
GENERAL AND SUPPORTIVE MEASURES
- Remove tick as soon as possible after detection.
MEDICINE TREATMENT
Antibiotic therapy
Treatment must be started before confirmation of diagnosis.
Severe disease:
- Doxycycline, oral.
- If < 50 kg: 4 mg/kg/24 hours in 2 divided doses on the first day, then 2 mg/kg/24 hours in 2 divided doses for second day.
- If > 50 kg: 100 mg 12 hourly for 2 days.
Then switch to:
- Azithromycin, IV/oral, 10 mg/kg daily for 3 days.
Mild to Moderate disease:
- Azithromycin, IV/oral, 10 mg/kg daily for 3 days.
REFERRAL
- Patients not responding to adequate therapy.
- Patients with complications.
Standard Treatment Guidelines and Essential Medicines List for South Africa Paediatric Hospital _2023, 5th edition_Updated July 2024
Chapter 8: Infective/Infectious Diseases, 8.21 Tick Bite Fever