Who this is for: GPs and medical officers seeing febrile adults and children in outpatient settings during dengue season, without inpatient beds or on-site platelet transfusion.

Epidemiology in Pakistan

Dengue is now endemic in Pakistan with epidemic surges each monsoon and post-monsoon season, typically August to November. The 2022 season alone produced more than 75,000 confirmed cases nationally, with Sindh, Punjab, KP and Islamabad all reporting sustained transmission. Urban centres such as Karachi, Lahore, Rawalpindi and Peshawar carry the heaviest burden, and all four dengue serotypes circulate, which raises the risk of secondary infection and severe disease. Case fatality stays below 1 percent where triage is done well, which makes the OPD assessment the single highest-leverage step.

Presentation and differentials

Classic dengue presents with abrupt high fever, retro-orbital headache, myalgia, arthralgia, flushed skin and sometimes a maculopapular rash around day 3 to 5. The illness runs in three phases: febrile (days 1 to 7), critical (around defervescence, lasting 24 to 48 hours, when plasma leakage occurs) and recovery. The counterintuitive teaching point for junior staff is that the dangerous window opens when the fever settles, not while it is high.

Differentials in a Pakistani OPD include malaria (do not skip a smear or RDT in endemic districts), enteric fever, chikungunya (more prominent arthritis), leptospirosis, and in children measles and other viral exanthems. Co-infection with malaria or typhoid is well documented, so a positive dengue test does not close the workup in a toxic-looking patient.

Diagnostic workup, cheapest first

  1. CBC is the workhorse. Progressive leukopenia followed by a falling platelet count and rising haematocrit is the classic pattern. Serial CBCs are more informative than any single value.
  2. NS1 antigen is positive from day 1 to about day 5 of fever and is widely available at private labs across Pakistan for a modest fee.
  3. Dengue IgM becomes reliable after day 5; order it when the patient presents late and NS1 is negative.
  4. A tourniquet test (positive if 10 or more petechiae per square inch) costs nothing and supports the diagnosis where labs are inaccessible.
  5. Reserve LFTs, ultrasound for ascites or gallbladder wall oedema, and chest imaging for patients with warning signs.

Do not wait for serology to start risk stratification; treat the syndrome.

Risk stratification per WHO classification

The WHO 2009 classification, carried forward in the WHO 2023 dengue clinical management update, sorts patients into three groups:

  • Dengue without warning signs (Group A): manage at home.
  • Dengue with warning signs (Group B): refer for observation and in-hospital monitoring.
  • Severe dengue (Group C): severe plasma leakage with shock or respiratory distress, severe bleeding, or severe organ involvement. Resuscitate and transfer urgently.

Memorise the WHO warning signs: abdominal pain or tenderness, persistent vomiting, clinical fluid accumulation (ascites, pleural effusion), mucosal bleeding, lethargy or restlessness, liver enlargement more than 2 cm, and a rising haematocrit with a rapidly falling platelet count. A haematocrit rise of 20 percent or more from baseline signals significant plasma leakage.

Groups that warrant a lower referral threshold even without warning signs: infants, pregnant women, adults over 65, obesity, diabetes, renal disease, patients on anticoagulants, and anyone who cannot return for daily review.

Management in the OPD

Group A (home care):

  • Oral fluids: ORS, fresh juices, soups; aim for urine output at least every 4 to 6 hours.
  • Paracetamol for fever: adults 500 to 1000 mg every 6 hours (maximum 4 g per day, lower ceiling in liver disease); children 15 mg per kg per dose.
  • Never prescribe aspirin, ibuprofen, diclofenac or any NSAID, and avoid intramuscular injections. This instruction must reach the family in plain language because over-the-counter NSAID use is common in Pakistan.
  • Daily review with CBC from day 3 of illness until 48 hours after defervescence.
  • There is no evidence-based role for papaya leaf extract or platelet-raising remedies; do not let them delay review.

Group B: insert an IV line if transfer will take time, start isotonic crystalloid (Ringer lactate or normal saline) at 5 to 7 ml per kg per hour if the patient cannot drink or the haematocrit is rising, and refer the same day with the CBC trend written on the referral slip.

Group C: this is an emergency. Give a 10 to 20 ml per kg crystalloid bolus for shock, keep the patient warm, and move to a facility with high-dependency care. Do not transfuse platelets for a number alone; prophylactic platelet transfusion is not recommended in the absence of significant bleeding.

Red flags and referral thresholds

Refer or admit for: any WHO warning sign, platelet count below 50,000 with a rising haematocrit, bleeding beyond petechiae, inability to maintain oral intake, altered mentation, hypotension or narrowing pulse pressure (20 mm Hg or less), pregnancy, infancy, and significant comorbidity. When in doubt during days 4 to 6 of illness, observe or refer; this is the leakage window.

Follow-up schedule

  • Daily clinical review and CBC from day 3 until 48 hours after fever settles.
  • At each visit reassess warning signs, oral intake, urine output and postural symptoms.
  • Recovery-phase patients may develop a confluent rash with islands of sparing and transient bradycardia; reassure and stop IV fluids to avoid overload.

Structured intake matters here: MyPatient AI-prepared intakes capture fever day, warning-sign screening and comorbidities before the consult, so the six-minute OPD visit can go to the CBC trend and the disposition decision. Share the patient guide to share so families know which danger signs mandate immediate return.

Key points

  • Risk-stratify every suspected dengue patient into WHO Groups A, B or C at every visit.
  • The critical phase begins at defervescence; days 4 to 6 are the danger window.
  • Serial CBC trends beat single values; a 20 percent haematocrit rise means leakage.
  • Paracetamol only; NSAIDs and aspirin are contraindicated.
  • Platelet count alone is not a transfusion trigger; bleeding and haemodynamics are.
  • Refer early for warning signs, pregnancy, infancy, comorbidity or poor access to review.

References

  • Dengue: Guidelines for Diagnosis, Treatment, Prevention and Control. World Health Organization, 2009.
  • Guidelines for the Clinical Management of Arboviral Diseases including Dengue. World Health Organization, 2023.
  • Handbook for Clinical Management of Dengue. World Health Organization and TDR, 2012.
  • National Guidelines for Dengue Prevention, Control and Management. Ministry of National Health Services, Government of Pakistan, 2019.
  • Comprehensive Guideline for Prevention and Control of Dengue. WHO Regional Office for South-East Asia, 2011.

Clinical judgement and local protocols take precedence.