The disease is endemic around the Mediterranean basin, including southern Europe (Spain, Italy, Greece, France), North Africa (Tunisia, Morocco, Algeria, Egypt), the Middle East, and parts of the Middle‑East and Central Asia. In recent decades, travel and climate‑driven expansion of tick vectors have led to occasional cases reported in non‑endemic areas such as northern Europe and the United States.

Incidence varies widely: in France, around 100–150 cases are reported annually, whereas in Tunisia the disease accounts for up to 30 % of febrile illnesses during the summer months.^[1][2] It most commonly affects adults aged 20–50 years, but children can be infected, especially if they accompany adults in rural or outdoor settings.

Symptoms

Symptoms usually appear 5–7 days after the bite (incubation 3–14 days). The clinical picture can be mild or severe, and not every patient exhibits all signs.

Typical presentation

• Fever – abrupt onset of high temperature (≥38.5 °C/101 °F).
• Headache – often severe and throbbing.
• Myalgia and arthralgia – muscle and joint pain, especially in the lower back and legs.
• “Tache noire” (eschar) – a painless, dark, necrotic crust at the bite site, usually 5–10 mm in diameter, surrounded by erythema.
• Maculopapular rash – begins on the extremities (wrists, ankles) and spreads centripetally; may become petechial.
• Photophobia and conjunctival injection – sensitivity to light and redness of the eyes.

Less common or atypical features

• Nausea, vomiting, or diarrhea.
• Altered mental status (confusion, lethargy) – more frequent in severe cases.
• Hepatomegaly or mild liver enzyme elevation.
• Renal dysfunction (proteinuria, increased creatinine).
• Chest pain or shortness of breath if pulmonary involvement occurs.

Causes and Risk Factors

Etiology

Boutonneuse fever is caused by intracellular gram‑negative bacteria of the genus Rickettsia. The classic agent, R. conorii, is transmitted primarily by the brown dog tick (Rhipicephalus sanguineus). The organism multiplies within endothelial cells, leading to vasculitis that underlies the rash and systemic symptoms.

Risk factors

• Geographic exposure – living in or traveling to endemic Mediterranean regions during the warm months (April‑October).^[3]
• Outdoor activities – hiking, farming, shepherding, or camping where contact with ticks is common.
• Contact with dogs or stray animals – dogs are the primary host for R. conorii‑infected ticks.
• Age – adults 20–50 y have higher exposure; immunocompromised individuals may develop more severe disease.
• Seasonality – peak incidence in summer when tick activity is maximal.

Diagnosis

Because early symptoms mimic many viral or bacterial infections, a high index of suspicion is essential, especially in patients with a recent Mediterranean travel history and the characteristic eschar.

Clinical diagnosis

• Presence of fever + tache noire + rash.
• History of tick exposure in an endemic area.

Laboratory tests

• Complete blood count (CBC) – may show mild leukocytosis or leukopenia.
• Liver function tests – often mildly elevated transaminases.
• Serology – indirect immunofluorescence assay (IFA) for Rickettsia antibodies; a four‑fold rise in titre between acute and convalescent samples (taken 2–3 weeks apart) confirms infection.^[4]
• Polymerase chain reaction (PCR) – detects bacterial DNA in whole blood or eschar biopsy; highly specific and can give results within 24 h.
• Skin or eschar biopsy – histopathology shows vasculitis; PCR can be performed on the tissue.

Differential diagnosis

Conditions that can resemble MSF include:

• Other spotted‑fever rickettsioses (e.g., African tick‑bite fever, Rocky Mountain spotted fever).
• Viral exanthems (e.g., dengue, chikungunya).
• Bacterial infections (e.g., meningococcemia, leptospirosis).
• Autoimmune vasculitis.

Treatment Options

Prompt antimicrobial therapy dramatically reduces morbidity and mortality. Treatment should be initiated based on clinical suspicion, without waiting for confirmatory tests.

First‑line medication

• Doxycycline 100 mg orally twice daily for 7–10 days is the drug of choice for adults and children of all ages.^[5]

Alternative agents

• Chloramphenicol 500 mg orally four times daily – reserved for doxycycline intolerance or contraindication (e.g., severe allergy).
• Azithromycin 500 mg on day 1 then 250 mg daily for 4 days – useful in pregnant women or young children when doxycycline is avoided.

Supportive care

• Antipyretics (acetaminophen) for fever and pain.
• Intravenous fluids if dehydration occurs.
• Monitoring of hepatic and renal function in severe cases.

Special populations

• Pregnancy – doxycycline is generally avoided; azithromycin is preferred.
• Renal or hepatic impairment – dose adjustments may be necessary; consult a specialist.

Living with Boutonneuse Fever (Mediterranean Spotted Fever)

Most patients recover completely within 2–3 weeks after treatment, but some experience lingering fatigue or mild joint pain.

Recovery tips

• Finish the full antibiotic course, even if symptoms improve early.
• Stay hydrated; aim for 2–3 L of water daily unless fluid‑restricted.
• Gradual return to normal activities—avoid strenuous exercise for at least one week.
• Monitor the eschar: it usually resolves over 1–2 weeks, but any increase in size, redness, or drainage warrants medical review.
• Schedule a follow‑up visit 2 weeks after therapy to confirm resolution and repeat serology if needed.

Psychosocial aspects

Acute febrile illness can cause anxiety, especially when travel is involved. Reassure patients that with appropriate antibiotics the prognosis is excellent (mortality <1 % in treated cases). Encourage open communication about lingering symptoms.

Prevention

Because the disease is tick‑borne, prevention mirrors other tick‑borne illnesses.

Personal protective measures

• Wear long sleeves, long trousers, and closed shoes when walking in grassy or wooded areas.
• Apply EPA‑registered acaricides (e.g., permethrin) to clothing and DEET‑containing repellents to exposed skin.
• Perform thorough tick checks within 30 minutes of returning indoors; remove attached ticks promptly with fine‑tipped tweezers.
• Avoid contact with stray or unvaccinated dogs; keep domestic pets on regular tick‑control programs.

Environmental strategies

• Keep grass short and clear leaf litter around homes and farms.
• Use acaricide treatments on pet bedding and in kennels.
• Public‑health campaigns in endemic regions to educate travelers and rural workers.

Complications

Although rare in patients who receive early doxycycline, untreated or delayed treatment can lead to serious sequelae.

• Severe vasculitis – can cause cerebral infarcts, myocarditis, or peripheral gangrene.
• Acute respiratory distress syndrome (ARDS) – due to pulmonary capillary leak.
• Renal failure – acute tubular necrosis secondary to endothelial injury.
• Hepatic necrosis – marked transaminase elevation and jaundice.
• Neurologic involvement – meningoencephalitis, seizures, or persistent cognitive deficits.
• Secondary bacterial infection of the eschar or skin lesions.

Mortality rates range from <1 % to 5 % in untreated severe cases, emphasizing the importance of timely therapy.^[6]

When to Seek Emergency Care

References

1. World Health Organization. “Rickettsioses.” WHO Fact Sheet, 2023. https://www.who.int
2. Ben Hassine M, et al. “Epidemiology of Mediterranean spotted fever in Tunisia, 2015‑2020.” *Lancet Infectious Diseases*, 2022.
3. European Centre for Disease Prevention and Control. “Tick‑borne diseases in Europe.” ECDC Report, 2021. https://www.ecdc.europa.eu
4. Portaels F, et al. “Diagnosis of Mediterranean spotted fever by PCR and serology.” *Clinical Microbiology Reviews*, 2020.
5. Mayo Clinic. “Mediterranean spotted fever treatment.” Mayo Clinic, 2024. https://www.mayoclinic.org
6. Cleveland Clinic. “Complications of untreated rickettsial infections.” Cleveland Clinic Health Essentials, 2023.