Dog bite in Pakistan: the rabies PEP decisions that actually matter

A dog bite is one of the most ordinary presentations in a Pakistani casualty department, and one of the few where getting the decision wrong is uniformly fatal. Rabies has essentially no treatment once symptoms appear — the entire clinical opportunity sits in the hours after the bite.

The decisions are genuinely simple once you know them. What complicates them here is that several widely-taught rules changed in WHO's 2018 position paper, and most of the references still in circulation predate it. This is what the current guidance actually says.

Before anything else: wash the wound

This is the single most effective intervention and the one most often rushed.

Immediate, thorough wound washing and flushing with soap and water, with copious amounts of water, is required. Where available, an iodine-containing, or similarly viricidal, topical preparation should be applied to the wound.

Not a rinse. Copious water, properly, before the paperwork and before the vaccine. Rabies virus is fragile outside the host and mechanical removal works.

One related point that gets forgotten in the suturing decision: wounds that require suturing should be sutured loosely, and only after immunoglobulin has been infiltrated into the wound. Closing a wound tightly before infiltration removes your chance to put the immunoglobulin where it needs to be.

The three categories

Everything follows from classifying the exposure.

Two things worth internalising. Bleeding is the dividing line between II and III for scratches — an abrasion that doesn't bleed is Category II, a scratch that breaches the skin is Category III. And bat contact is always Category III, regardless of whether there's a visible wound, because bat bites can be trivial to see.

The vaccine regimens

For a patient with no previous rabies vaccination, WHO accepts any one of three schedules:

The intradermal regimen deserves attention in Pakistani practice. It uses substantially less vaccine, finishes in a week rather than a month, and WHO notes that its cost-effectiveness increases with the number of patients a clinic sees — which describes a busy anti-rabies centre precisely. A one-week course also has an obvious advantage the guidelines don't spell out: a patient who has to return four times over a month is a patient with four chances to drop out.

If they've been vaccinated before

Much shorter, and immunoglobulin is never indicated — not even for Category III. Any one of:

• 1 site intradermally on days 0 and 3
• 4 sites intradermally on day 0
• 1 site intramuscularly on days 0 and 3

That "no immunoglobulin even for Category III" is counter-intuitive and worth remembering. A previously immunised patient has memory B cells; passive antibody adds nothing and may blunt the anamnestic response.

And if they finished a course recently

If a repeat exposure occurs within 3 months of completion of PEP, only wound treatment is required, neither vaccine nor RIG are needed.

Worth asking about directly. In areas with a lot of stray dogs, re-presentation within three months is not unusual, and these patients are routinely given a full unnecessary course.

Immunoglobulin: three things that changed

This is where the older teaching is now actively wrong.

1. Don't give the remainder intramuscularly

The maximum dose is 20 IU/kg for human RIG and 40 IU/kg for equine RIG. But WHO is now explicit that this is a ceiling, not a target — there is no minimum dose. And critically:

Infiltrate as much as possible into the wound; the remainder of the calculated dose of RIG does not need to be injected IM at a distance from the wound but can be fractionated in smaller, individual syringes to be used for other patients.

The old practice — calculate by weight, infiltrate what fits, inject the rest into the gluteal region — is obsolete. Immunoglobulin works by neutralising virus at the wound site; antibody deposited in a distant muscle does very little. In a country where RIG is often in short supply, that leftover is not waste to be injected somewhere harmless — it is another patient's dose.

2. Stop skin-testing before equine RIG

As eRIG products are now highly purified, skin testing before administration is unnecessary and should be abandoned.

Skin testing does not predict anaphylaxis reliably, and it delays treatment. Modern eRIG has a safety profile close to hRIG at a fraction of the cost.

3. Never withhold vaccine because immunoglobulin isn't available

If RIG is not available, thorough, prompt wound washing, together with immediate administration of the first vaccine dose, followed by a complete course of rabies vaccine, is highly effective in preventing rabies. Vaccines should never be withheld, regardless of the availability of RIG.

This matters enormously here. A patient sent away to "come back when immunoglobulin arrives" is a patient who may not come back. Start the vaccine.

And when supply is limited, WHO gives an explicit prioritisation list rather than leaving it to instinct — reserve immunoglobulin for:

• Multiple bites
• Deep wounds
• Bites to highly innervated parts of the body — head, neck and hands
• Severe immunodeficiency
• A biting animal that is a confirmed or probable rabies case
• Bites, scratches or mucous-membrane exposures caused by a bat

Immunoglobulin is given once only, as soon as possible after PEP starts, and not beyond day 7 after the first vaccine dose. After that the patient's own antibody response is under way and passive antibody interferes with it.

Practical points that prevent avoidable failures

• A delayed dose means resume, not restart. Patients miss day 3 and get told to begin again — unnecessary, and it wastes vaccine.
• Switching product or route mid-course is acceptable if it's unavoidable to get the course finished. Finishing on a different brand beats not finishing.
• Documented immunodeficiency is assessed case by case and gets a complete ID or IM course including immunoglobulin.
• Ask about the animal, but don't wait for it. Observation of a healthy domestic dog can inform stopping PEP later; it never justifies delaying the first dose.

Bottom line

Wash the wound properly and first. Classify honestly — bleeding separates II from III, and bats are always III. Give the vaccine, and prefer the one-week intradermal course where your centre offers it. For Category III in an unvaccinated patient, infiltrate immunoglobulin into the wound and don't inject the remainder into a buttock. Don't skin-test eRIG. And never let absent immunoglobulin stop you starting the vaccine.

Our rabies PEP tool walks through this in five steps — exposure category, vaccination history, regimen, immunoglobulin and wound care — with the immunoglobulin dose shown as a ceiling rather than a target, and every step citing its section of the WHO paper.

ReviseFCPS1 is built by doctors in Pakistan, for doctors in Pakistan. Our clinical tools are free, including the Pakistan EPI vaccination schedule, the dengue triage and fluid wizard and the typhoid management wizard. If you are preparing for FCPS Part 1, try it free for 7 days — 10,176 doctor-verified MCQs and 8,236 real exam recalls.