Chikungunya fever is an acute arboviral illness transmitted by Aedes mosquitoes, characterized by sudden-onset high fever (>39°C) and debilitating symmetric polyarthralgia, with no specific antiviral treatment available. [1-3] The following figure illustrates the clinical timeline of infection, symptoms, and biomarkers:
1. History
- Onset and timing: Abrupt onset of high fever after an incubation period of 3–7 days (range 1–12 days); fever typically lasts ≤1 week and can be biphasic [2-3]
- Travel history: Essential — ask about travel to endemic areas (Southeast Asia, Indian subcontinent, sub-Saharan Africa, Caribbean, Latin America, Pacific Islands) within the prior 2 weeks [2]
- Arthralgia characterization: Severe, symmetric, bilateral polyarthralgia involving both large and small joints (hands, feet, wrists, ankles); pain so intense patients may be unable to move from the position they were in at onset [3]
- Associated symptoms: Maculopapular rash (trunk, extremities, palms/soles), myalgia, headache, conjunctivitis, nausea/vomiting, fatigue, anorexia [2-3]
- Important negatives: Absence of significant hemorrhagic manifestations, absence of thrombocytopenia, and absence of respiratory/GI symptoms help distinguish from dengue [4]
2. Alarm Features
- Hemodynamic instability — hypotension, tachycardia, signs of shock [5]
- Neurological involvement — altered mental status, seizures, focal deficits (meningoencephalitis, Guillain-Barré syndrome, myelitis, cranial nerve palsies) [1-2]
- Cardiovascular decompensation — myocarditis, arrhythmias [1][5]
- Hemorrhagic signs — though rare in chikungunya, must exclude dengue coinfection [5]
- Respiratory failure, acute hepatitis, or acute renal failure [5]
- Severe bullous skin lesions (especially in children) [2]
- Neonates exposed intrapartum — risk of hemorrhagic symptoms, myocardial disease, neurologic disease [2]
- High-risk groups: Neonates, adults >65 years, patients with comorbidities (diabetes, heart disease, hypertension) — mortality risk increases 79-fold in those ≥60 years compared to 20–29-year-olds [2][6]
3. Medications
- First-line analgesia/antipyretic: Acetaminophen (paracetamol) — preferred until dengue is ruled out to avoid hemorrhagic risk; max 4 g/24 h, avoid in liver disease [2][5]
- NSAIDs: Can be used once dengue is excluded; effective for fever and joint pain. However, guidelines are contradictory — some advise caution due to risk of acute kidney injury and potential association with severe disease [5]
- Avoid aspirin/salicylates in the acute phase due to hemorrhage risk [5]
- Escalation for refractory pain: Tramadol, codeine, or opiates alone or in combination with paracetamol [5]
- Antihistamines: For pruritic rash (recommended by 39% of global guidelines) [5]
- Corticosteroids: Controversial in acute phase — some evidence of pain reduction when added to NSAIDs, but risk of rebound symptoms and immunosuppression; more accepted in subacute/chronic arthralgia [2][5]
- Chronic arthralgia: NSAIDs, corticosteroids, hydroxychloroquine, methotrexate, and physical therapy for persistent symptoms [2-3][7]
- No approved antivirals — ribavirin, favipiravir, and interferon-α have in vitro activity but no clinical evidence of efficacy [3][8-9]
4. Diet
- Hydration is critical — oral rehydration for mild cases; IV fluids for those unable to tolerate PO or with hemodynamic compromise [2][5]
- Rest — recommended during the acute febrile phase [2][5]
- Cold compresses to affected joints may provide symptomatic relief [5]
- No specific dietary triggers or restrictions; standard supportive nutrition during acute illness
5. Review of Systems
- MSK: Joint pain/swelling (symmetric, bilateral), joint stiffness, periarticular edema, back pain
- Dermatologic: Maculopapular rash, pruritus, bullous lesions (children)
- Ophthalmologic: Conjunctivitis, eye pain (uveitis, retinitis in severe cases)
- Neurologic: Headache, altered sensorium, weakness, paresthesias
- Cardiovascular: Chest pain, palpitations, dyspnea
- GI: Nausea, vomiting, abdominal pain (less common than in dengue)
- Renal: Decreased urine output
- Constitutional: Intense fatigue, asthenia, anorexia
6. Collateral History and Family History
- Household contacts with similar symptoms (cluster outbreaks suggest local transmission)
- Co-travelers with febrile illness
- Mosquito exposure history — outdoor activities, lack of repellent/bed nets, standing water near residence
- Prior arboviral infections — previous dengue or Zika (affects serologic interpretation due to cross-reactivity)
- Pregnancy status — intrapartum transmission risk to neonate [2]
- Family history is generally not contributory, though comorbidities (diabetes, hypertension, cardiac disease) in the patient increase risk of severe disease [2][6]
7. Risk Factors
- Travel to or residence in endemic areas (tropical/subtropical regions with Aedes mosquito populations) [1][5]
- Age extremes: Neonates and adults >65 years at highest risk for severe/atypical disease and death [2][6]
- Comorbidities: Diabetes, hypertension, cardiovascular disease, chronic kidney disease [2][6]
- Lack of prior immunity — naïve populations experience high attack rates; >85% of infected individuals are symptomatic [3]
- Rainy season/post-monsoon — peak mosquito breeding periods
- Urban settings with poor vector control [5]
8. Differential Diagnosis
The CDC recommends considering the following in the differential: [2]
- Dengue fever — more headache, retro-orbital pain, thrombocytopenia, leukopenia, hemorrhagic manifestations; less prominent arthralgia [4][10-11]
- Zika virus — lower-grade or absent fever, prominent pruritic rash, conjunctivitis; less arthralgia [11]
- Malaria — cyclical fevers, rigors, hepatosplenomegaly; thick/thin smear diagnostic
- Leptospirosis — conjunctival suffusion, jaundice, renal failure, exposure history
- Other alphaviruses — Mayaro, O'nyong-nyong, Ross River, Sindbis (similar arthritogenic presentation) [2][12]
- Measles/Rubella — rash characteristics, vaccination history, Koplik spots
- Parvovirus B19 — symmetric polyarthralgia, "slapped cheek" rash
- Reactive/postinfectious arthritis — temporal relationship to preceding infection
- Acute rheumatoid arthritis — chronic chikungunya can mimic RA [3]
- Group A Streptococcus, typhus, enteroviral disease [2]
Key distinguishing features of chikungunya: Debilitating polyarthralgia (PPV >80% for CHIKV viremia in endemic areas), absence of thrombocytopenia, joint swelling/edema, and rash — in contrast to dengue which features thrombocytopenia, leukopenia, and warning signs of plasma leak [3-4]
9. Past Medical History
- Chronic conditions — diabetes, hypertension, heart disease, CKD increase risk of severe/atypical disease and death [2][6]
- Prior arboviral infections — affects serologic interpretation; prior CHIKV infection likely confers lifelong immunity
- Immunosuppression — may alter disease course
- Liver disease — relevant for acetaminophen dosing [5]
- Renal disease — caution with NSAIDs [5]
- Pregnancy — risk of intrapartum transmission; spontaneous abortion reported after first-trimester infection [2]
10. Physical Exam
- Vitals: High fever (typically >39°C/102°F), tachycardia; hypotension is a red flag [2-3]
- MSK: Symmetric polyarthritis/polyarthralgia, periarticular edema (especially interphalangeal joints, wrists, ankles), tenderness along ligament insertions [3]
- Skin: Maculopapular rash on trunk and extremities (may involve palms, soles, face); can be bullous in children; pruritic [2-3]
- Eyes: Bilateral non-purulent conjunctivitis [1]
- Lymph nodes: Mild lymphadenopathy may be present
- Neuro: Assess for meningismus, focal deficits, altered consciousness (suggests atypical/severe disease)
- Cardiovascular: Assess for signs of myocarditis (new murmur, gallop, JVD)
- Tourniquet test: May help differentiate from dengue (more often positive in dengue)
11. Lab Studies
- CBC: Lymphopenia is common; thrombocytopenia is typically mild or absent (in contrast to dengue where it is prominent) [2][4][13]
- CMP: Elevated creatinine and liver function tests (AST/ALT) may be seen [2]
- CRP/ESR: Elevated in acute phase
- Confirmatory testing:
- RT-PCR (viral nucleic acid detection) — most useful in the first week of illness during viremia [2][7]
- IgM serology — develops toward end of first week; can persist months to years; may cross-react with other alphaviruses [2]
- IgG serology — appears 4–10 days after onset; persists for years [3]
- Plaque reduction neutralization test (PRNT) — confirmatory, discriminates cross-reacting antibodies [2]
- Rule-out labs: Dengue NS1 antigen, dengue IgM/IgG, malaria smear, blood cultures if bacterial infection suspected
12. Imaging
- Not routinely indicated in uncomplicated chikungunya
- Joint imaging (X-ray, ultrasound): Consider if chronic arthritis develops — may show periarticular soft tissue swelling; erosive changes can occur in chronic disease mimicking RA [3]
- Chest X-ray: If respiratory symptoms or suspected myocarditis/pulmonary edema
- CT/MRI brain: If neurological involvement suspected (encephalitis, myelitis)
- Echocardiography: If myocarditis suspected
13. Special Tests
- Clinical prediction rule for chikungunya (validated in dengue-endemic areas): Fever (1 pt) + exanthema (1 pt) + myalgia (2 pts) + arthralgia/arthritis (2 pts) + joint edema (2 pts); score ≥4 has 74% sensitivity and 52% specificity [14]
- Point-of-care rapid diagnostic tests: Chikungunya IgM rapid tests available in some settings
- Viral culture: Gold standard but impractical for clinical use; reserved for reference laboratories [7]
- Tourniquet test: Helps differentiate from dengue (more often positive in dengue)
14. ECG
- Indicated if: Chest pain, dyspnea, palpitations, or clinical suspicion of myocarditis
- Findings in myocarditis: ST-segment changes, T-wave inversions, conduction abnormalities, arrhythmias
- Routine ECG not required in uncomplicated cases
- Consider troponin and echocardiography if ECG abnormalities detected
15. Assessment
Typical presentation: Abrupt-onset high fever with severe symmetric polyarthralgia, maculopapular rash, myalgia, and conjunctivitis in a patient with recent travel to an endemic area. Acute symptoms resolve in 7–10 days. [2]
Severity stratification
- Non-severe (majority): Self-limited febrile illness with polyarthralgia; manageable as outpatient
- Severe/atypical (rare): Organ involvement — myocarditis, encephalitis, hepatitis, renal failure, hemorrhage; requires hospitalization [5]
Chronic phase: 30–50% of patients develop persistent or relapsing polyarthralgia lasting months to years, which can mimic rheumatoid arthritis and cause significant disability [3][5]
Complications: Myocarditis, meningoencephalitis, Guillain-Barré syndrome, myelitis, uveitis/retinitis, acute hepatitis, renal failure, severe bullous lesions, neonatal disease from intrapartum transmission [1-2]
16. Treatment Plan
Initial stabilization (ED)
- ABCs; IV access if hemodynamically unstable or unable to tolerate PO
- IV fluid resuscitation for dehydration or shock [5]
Acute management
- Acetaminophen 500–1000 mg PO q6h (max 4 g/day) as first-line for fever and pain — preferred until dengue excluded [2][5]
- NSAIDs (ibuprofen, naproxen) once dengue ruled out — effective for arthralgia and inflammation [2][5]
- Tramadol or codeine for pain refractory to acetaminophen/NSAIDs [5]
- Antihistamines (cetirizine, diphenhydramine) for pruritic rash [5]
- Oral rehydration — encourage adequate fluid intake [2]
- Rest and cold compresses to affected joints [5]
Subacute/chronic arthralgia (>2 weeks)
- NSAIDs as mainstay
- Short-course corticosteroids (e.g., prednisone) with caution — risk of rebound [2][5]
- Physical therapy for persistent joint symptoms [2]
- Hydroxychloroquine or methotrexate for chronic inflammatory arthritis refractory to NSAIDs — used off-label with variable success [3][7]
Severe/atypical disease
- ICU admission for organ failure, hemodynamic instability
- IV fluids, vasopressors as needed
- Blood products for hemorrhage [5]
- Organ-specific supportive care (ventilatory support, renal replacement therapy)
17. Disposition
Discharge criteria (majority of cases)
- Hemodynamically stable, tolerating PO fluids
- Pain controlled with oral analgesics
- No signs of severe/atypical disease
- Reliable follow-up and return precautions understood
Admission criteria: [5]
- Hemodynamic instability or signs of shock
- Atypical manifestations (neurologic, cardiac, hepatic, renal involvement)
- Severe pain unresponsive to oral analgesia
- Signs of hemorrhage
- Decompensation of underlying comorbidities
- Neonates with perinatal exposure
- Inability to tolerate oral intake / severe dehydration
Specialist consultation triggers
- Rheumatology — chronic/refractory arthralgia
- Infectious disease — diagnostic uncertainty, severe/atypical disease
- Neurology — encephalitis, GBS, myelitis
- Cardiology — suspected myocarditis
- Ophthalmology — uveitis, retinitis
18. Follow Up / Return Precautions
Follow-up timing
- Primary care follow-up within 1–2 weeks for symptom reassessment
- Earlier if symptoms worsen or new symptoms develop
- Rheumatology referral if joint symptoms persist beyond 4–6 weeks
Return precautions — instruct patients to return immediately for:
- Worsening fever or new fever after initial resolution
- Bleeding (gums, nose, GI, vaginal)
- Severe abdominal pain, persistent vomiting
- Altered mental status, seizures, weakness
- Chest pain, shortness of breath
- Decreased urine output
- Inability to tolerate fluids
Patient counseling
- Acute symptoms typically resolve in 7–10 days [2]
- Joint pain may persist for weeks to months in up to 30–50% of patients — this is expected and does not indicate a new infection [5]
- Mosquito bite prevention during the first week of illness to prevent onward transmission (bed nets, repellent, long sleeves) [2]
- Report to local health department — chikungunya is a nationally notifiable disease [2]
References
1. Chikungunya: Epidemiology, Pathogenesis, Clinical Features, Management, and Prevention. — Vairo F, Haider N, Kock R, et al. Infectious Disease Clinics of North America. 2019.
2. Chikungunya. — J. Erin Staples, Susan L. Hills, and Ann M. Powers CDC Yellow Book. 2026.
3. Chikungunya Virus and the Global Spread of a Mosquito-Borne Disease. — Weaver SC, Lecuit M. The New England Journal of Medicine. 2015.
4. Distinguishing Patients With Laboratory-Confirmed Chikungunya From Dengue and Other Acute Febrile Illnesses, Puerto Rico, 2012-2015. — Alvarado LI, Lorenzi OD, Torres-Velásquez BC, et al. PLoS Neglected Tropical Diseases. 2019.
5. An Evaluation of Global Chikungunya Clinical Management Guidelines: A Systematic Review. — Webb E, Michelen M, Rigby I, et al. EClinicalMedicine. 2022.
6. Chikungunya Virus Virus-Like Particle Vaccine Safety and Immunogenicity in Adults Older Than 65 Years: A Phase 3, Randomised, Double-Blind, Placebo-Controlled Trial. — Tindale LC, Richardson JS, Anderson DM, et al. Lancet. 2025.
7. Chikungunya Infection: A Global Public Health Menace. — Mathew AJ, Ganapati A, Kabeerdoss J, et al. Current Allergy and Asthma Reports. 2017.
8. Chikungunya: A Re-Emerging Virus. — Burt FJ, Rolph MS, Rulli NE, Mahalingam S, Heise MT. Lancet. 2012.
9. Chikungunya Virus: An Update on the Biology and Pathogenesis of This Emerging Pathogen. — Burt FJ, Chen W, Miner JJ, et al. The Lancet. Infectious Diseases. 2017.
10. Symptom Overlap in Chikungunya and Dengue: A Diagnostic Challenge During Outbreaks. — Brancini ML, Sene FCT, Pereira Dos Santos TF, et al. Acta Tropica. 2026.
11. Comparison of Dengue, Chikungunya, and Zika Among Children in Nicaragua Across 18 Years: A Single-Centre, Prospective Cohort Study. — Carrillo FAB, Ojeda S, Sanchez N, et al. The Lancet. Child & Adolescent Health. 2025.
12. Arthritogenic Alphaviruses: Epidemiological and Clinical Perspective on Emerging Arboviruses. — Zaid A, Burt FJ, Liu X, et al. The Lancet. Infectious Diseases. 2021.
13. Comparison of Clinical Presentation and Out-Comes of Chikungunya and Dengue Virus Infections in Patients With Acute Undifferentiated Febrile Illness From the Sindh Region of Pakistan. — Shahid U, Farooqi JQ, Barr KL, et al. PLoS Neglected Tropical Diseases. 2020.
14. Development and Validation of a Clinical Rule for the Diagnosis of Chikungunya Fever in a Dengue-Endemic Area. — Batista RP, Hökerberg YHM, de Oliveira RVC, Lambert Passos SR. PloS One. 2023.