Level 1 of 6Core
Rabies: post-exposure prophylaxis and established disease
The core to-do list — diagnose and manage, at a glance
Diagnose— recognise it
- Decide first which of two diseases you have: a rabies *exposure* is an asymptomatic person bitten, scratched or licked by a potentially rabid mammal — a preventable event and a therapeutic emergency; *established rabies* is a symptomatic encephalitis or ascending paralysis — a palliative problem. Confusing the two tempos is the central error in this field.
- Grade the exposure by WHO category: I — touching or feeding animals, licks on *intact* skin (no exposure); II — nibbling of uncovered skin, minor scratches without bleeding (vaccine, no immunoglobulin); III — transdermal bites or scratches, licks on broken skin, saliva on mucous membranes, or any direct contact with a bat (immunoglobulin AND vaccine). When in doubt treat as Category III; an escaped animal is considered rabid; in severe immunosuppression Category II is managed as III.
- Know which animals matter: dogs cause about 99% of human rabies; cats are a genuine, under-recognised risk; a bat bite may leave no visible mark; rodents, rabbits, hares, birds, reptiles and fish are not implicated. Bite anatomy predicts risk — from about 10% for bites on the legs to 80% for bites on the head.
- In the symptomatic patient the one specific clue is paraesthesiae, pain or pruritus at or near the exposure site (50–80% of patients) after a 2–10 day influenza-like prodrome; the incubation period is usually 20–90 days and may exceed a year, so the wound is usually long healed — ask every encephalitic or weak patient about odd sensation, then inspect the site.
- Recognise the two forms of established disease: encephalitic (furious, about 80%) — delirium alternating with calm, hyperexcitability to noise and light, hydrophobia in about 50%, and aerophobia, which is pathognomonic; paralytic (dumb, about 20%) — symmetrical ascending flaccid paralysis resembling Guillain–Barré, often starting in the bitten limb, without hydrophobia. Death usually occurs 10–14 days after symptom onset.
- No laboratory test tells you whether a patient needs prophylaxis — the decision is clinical and epidemiological; in high-risk exposures and canine-endemic areas prophylaxis is started without waiting for laboratory results.
Manage now— do this, in order
- Wash the wound first: copious irrigation with soap and running water for a full 15 minutes, timed. Povidone-iodine is applied after, not instead of, the wash. Irrigate deep punctures under pressure with sterile 0.9% sodium chloride; excise devitalised tissue conservatively. If pain prevents washing, give paracetamol 1 g orally or IV (child 15 mg/kg) with morphine 2.5–5 mg IV titrated (child 0.1 mg/kg) first.
- Do not suture the wound — closure traps virus and bacteria in an anaerobic space and drives inoculum along tissue planes; unavoidable closure of a large facial wound follows full irrigation and immunoglobulin infiltration, with the loosest apposition and drainage.
- Give rabies immunoglobulin on day 0 for every Category III exposure in a previously unvaccinated patient: HRIG 20 IU/kg (or purified equine ERIG 40 IU/kg) as a single total dose, weighing the patient. Infiltrate as much as possible into and around the wound; give the remainder IM distant from the vaccine. If the volume will not cover multiple wounds, dilute two- to threefold in sterile 0.9% sodium chloride — dilute, never exceed the dose. Never give it to someone with a documented complete previous course, and never beyond day 7 after the first vaccine dose.Doctor / Nurse
- Give the vaccine on the day of presentation: one full dose IM on days 0, 3, 7 and 14 (Essen regimen) — WHO accepts the final dose between day 14 and 28, and a late fourth dose is far better than an omitted one. Into the deltoid (anterolateral thigh under 2 years) — never the gluteal muscle, where failures are documented. The vaccine dose is not weight-based: a neonate receives the same full dose as a 100 kg adult. Documented complete previous course: two boosters days 0 and 3, no immunoglobulin. Severe immunosuppression: five doses (0, 3, 7, 14, 28) plus immunoglobulin for any category.Doctor / Nurse
- Cover the bacterial infection and the tetanus: co-amoxiclav 875/125 mg orally 12-hourly (children 45 mg/kg/day of the amoxicillin component in two divided doses), prophylaxis usually 3–5 days; IV options ampicillin/sulbactam 3.0 g 6-hourly or ceftriaxone 2 g once daily plus metronidazole 500 mg 8-hourly. Every bite is a tetanus-prone wound — booster if none in the past 5 years; immunise plus tetanus immune globulin if the primary course was never completed.
- Rescue the deviations: treat a late presentation in full as if the bite were today; resume and complete an interrupted course rather than restarting; if vaccine was given gluteally, repeat it in the deltoid and recount the schedule from that day. There are no contraindications to post-exposure prophylaxis — not pregnancy, breastfeeding, infancy or immunosuppression.
- In established rabies, palliate: quiet darkened single room; gown, gloves, eye protection and mask with strict sharps discipline (saliva is infectious); IV access early and everything parenteral, since swallowing provokes agonising spasm. Diazepam 5–10 mg IV slowly repeated as required or midazolam 2–5 mg IV; morphine 2.5–5 mg IV titrated to comfort; chlorpromazine 25–50 mg IM for agitation — in a uniformly fatal disease under-sedation is the error. Treat the treatable alternatives empirically: aciclovir 10 mg/kg IV 8-hourly (renally adjusted) and antibiotics for possible bacterial meningitis; give full prophylaxis to every contact with Category II or III exposure to the patient's saliva.Doctor / Nurse
| WHO category | Definition | Action |
|---|---|---|
| I | Touching/feeding animals; licks on intact skin | Wash; no prophylaxis |
| II | Nibbling of uncovered skin; minor scratches without bleeding | Wash + vaccine |
| III | Transdermal bites/scratches; licks on broken skin; saliva on mucous membranes; any bat contact | Wash + immunoglobulin + vaccine |
Refer / escalate
Refer urgently for surgical assessment of extensive facial, hand or over-joint wounds, a scalp bite in a small child, or a neck bite with expanding haematoma or stridor; escalate immediately for any suspected established rabies (hydrophobia, aerophobia, hypersalivation with inability to swallow, agitation alternating with lucidity, paraesthesiae at an old healed wound, unexplained encephalitis from an endemic area, or ascending paralysis with fever) for barrier precautions, palliation and identification of contacts.
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