Reasoning GP · Algorithm · 1-page summary
Facial swelling — new presentation
For: adults and children with new facial swelling, face to face or remote. Not for: eyelid-only swelling (Eye swelling) or a neck lump alone (Neck lump). Doses shown are adult.
Core rule: check the airway first. Lip, tongue or throat swelling, or floor-of-mouth swelling with trismus, is an airway emergency. A dental abscess needs drainage; antibiotics never replace it.
0Stop — call 999 now — before any history
- Lip, tongue or throat swelling with airway, breathing or circulation compromise → 999 + IM adrenaline 500 micrograms (0.5 mL of 1 mg/mL) into the anterolateral thigh; repeat after 5 min if problems persist.
- Ludwig's angina or deep neck-space infection: bilateral floor-of-mouth swelling, raised tongue, trismus, drooling, muffled voice, stridor → 999. No extensive mouth examination.
- Fever, unwell, rapidly spreading swelling or crepitus (necrotising infection) · orbital signs (proptosis, restricted eye movement, visual loss) · cavernous sinus thrombosis (severe headache, fever, eye signs, confusion) → 999
- While waiting: sit up only if needed to breathe, else lie flat; no walking. Watch continuously; do not delay transfer for imaging. ACE-inhibitor or hereditary angio-oedema often does not respond to adrenaline, antihistamines or steroids.
1Triage by onset and pattern
| Pattern | Think → go to |
|---|---|
| Minutes | Angio-oedema or allergy → airway check, block 0 |
| Hours, painful, fever | Dental abscess, cellulitis, parotitis |
| Worse on eating | Salivary stone (mealtime swelling) |
| Days–weeks, painless | Tumour or lymph node → cancer row, block 2 |
| Face + arm + neck | Dilated neck veins, plethora → SVC obstruction, block 2 |
2Screen — one row is enough
- Suspected SVC obstruction → Same-day hospital (acute oncology / A&E), kept upright; stridor, cerebral symptoms, syncope or severe breathlessness → 999
- Trismus, spreading dental infection, deep facial-space infection, suppurative parotitis with systemic illness → Same-day OMFS / ENT. Cellulitis near the eye or nose: low threshold for the same.
- Persistent unexplained neck lump (any age; also ≥45 laryngeal), unexplained adult lymphadenopathy, suspicious oral lesion → consider Suspected cancer pathway (NG12)
- Persistent or progressive unexplained unilateral parotid, submandibular or facial swelling, or cranial-nerve deficit with a mass → Urgent local head and neck pathway.
- Unexplained facial injury; bruising or petechiae in a young child → Same-day paediatrics + safeguarding. Domestic abuse → DASH / MARAC.
3Assess — only once blocks 0–2 are answered
☐ Airway: voice, swallowing, drooling, stridor (concern → 999, stop examining) ☐ Face: symmetry, warmth, fluctuance, pitting or not, earlobe pushed out ☐ Mouth: teeth, floor of mouth bimanually, Stensen's duct pus ☐ Eye movements and vision ☐ All neck nodes, incl. supraclavicular ☐ ACE inhibitor, steroids, new drugs
FBC, CRP, renal function, glucose only if infection or systemic illness. Not GP tests: OPG (dental-led), CT/MRI, blanket panels.
4Classify — only if the screen is negative
- Dental abscess — commonest unilateral cause; tender swelling over a tooth → dentist same day or within 24 h (NHS 111 out of hours).
- Angio-oedema — non-pitting, not itchy. With urticaria = allergic; without = ACE inhibitor or hereditary (bradykinin).
- Cellulitis / erysipelas — hot, red, well-demarcated plaque, fever.
- Parotitis — mumps: bilateral, unvaccinated, notifiable. Bacterial: unilateral, pus from Stensen's duct, elderly or dehydrated.
- Salivary stone — swelling and pain with meals; hydration, massage, sour sweets.
- Uncertain — say so; a persistent painless swelling is not "just a gland". Refer per block 2 or set a review date.
5Treat today — doses: NICE/SPC, BNF, local formulary
- Dental abscess: dental drainage. Antibiotics only for spreading infection, systemic illness, significant trismus, no prompt drainage or high risk: amoxicillin 500 mg TDS 5 days (penicillin allergy: metronidazole 400 mg TDS 5 days).
- Cellulitis: flucloxacillin 500 mg–1 g QDS 5–7 days; near the eyes or nose co-amoxiclav 500/125 mg TDS 7 days (allergy: clarithromycin + metronidazole).
- Allergic angio-oedema: non-sedating antihistamine; short prednisolone only if severe. ACE-inhibitor angio-oedema: stop it for good, record as allergy; ARB only after specialist risk discussion.
- Mumps: supportive; off school or work 5 days from swelling onset; notify UKHSA; check MMR.
6Refer routinely
- Recurrent angio-oedema (possible hereditary) → allergy / immunology (C4, C1-INH via their pathway).
- Stone not passing, or parotid mass for FNA → OMFS.
- Parotid swelling with dry eyes and mouth (Sjögren's) → rheumatology. Convincing Cushing's features → endocrine pathway, not for isolated facial swelling.
7Never reassure by
- A course of antibiotics: an abscess needs drainage; never rotate courses.
- Antihistamines or steroids for ACE-inhibitor or hereditary angio-oedema.
- Painlessness: firm, progressive, painless swelling is the cancer pattern.
- "Bell's palsy" when facial weakness comes with parotid swelling.
- Watching an unexplained node for 6 weeks before referring.
- A GP dexamethasone "bridge" for SVC obstruction.
8Safety-net — say it, then document it
999 “Call 999 if your lips, tongue, mouth or throat swell and you have any trouble breathing, swallowing or speaking, drooling or noisy breathing; if the swelling spreads into your neck; or if your eye bulges, hurts to move or your vision changes.”
Same day: “If the swelling spreads, you can't open your mouth fully, or your fever gets worse on antibiotics — go to A&E or contact us today.” Review dental abscess at 24–48 h, parotitis at 48 h. No dentist → A&E.
✓Safe to leave primary care only if — all five, documented
Airway, eyes and deep spaces clear; no block 0–2 row
Mouth, face and neck nodes examined
Cause named, or uncertainty stated with a review date
Dental slot confirmed or ACE inhibitor stopped and recorded
Safety-net given; written for home management
Summary of the full Reasoning GP facial swelling algorithm, which holds the detail, examination, differentials and evidence. Sources: Resuscitation Council UK anaphylaxis (2021); NICE NG141, NG12 (updated April 2026); UKHSA mumps guidance; local antimicrobial and dental pathways; BAOMS. Clinical reference — follow local emergency-transfer policies and check doses: NICE/SPC, BNF.