Ludwig's angina is a polymicrobial cellulitis of the submandibular, submental, and sublingual spaces — it arises almost exclusively from an infected lower second or third molar tooth. The infection spreads along fascial planes and does not spontaneously drain. The raised tongue and floor-of-mouth swelling can displace the tongue posteriorly, directly obstructing the oropharynx — death from asphyxiation can occur within hours. It is one of the true dental emergencies that GPs must recognise. The clinical features are pathognomonic: bilateral submandibular swelling that is brawny (indurated), tender, and "woody" in texture (not fluctuant — it is cellulitis not abscess), elevation of the tongue, trismus, drooling, and a characteristic "bull neck" appearance. Any trismus combined with floor-of-mouth swelling in the context of recent dental pain = Ludwig's angina until proven otherwise = 999. SVC obstruction from malignancy is a genuine emergency — dexamethasone 8 mg IV (or oral if IV unavailable) should be given immediately in primary care before transfer, as it reduces tumour oedema and can temporarily relieve SVC compression while definitive treatment (stenting or radiotherapy) is arranged. GPs should be familiar with Pemberton's sign: raising both arms above the head causes worsening facial plethora and sometimes syncope due to further narrowing of the thoracic inlet by the raised arms — it is pathognomonic of SVC obstruction.

The parotid gland is one of the most anatomically specific structures in facial swelling — it lies anterior to and below the ear, and swelling of the parotid pushes the earlobe outward (a characteristic sign). Stensen's duct opens at the parotid papilla opposite the upper second molar tooth — purulent discharge from this opening confirms acute suppurative parotitis. The most important clinical distinction for a parotid mass is between inflammatory (warm, tender, associated with systemic upset, bilateral in viral parotitis) and neoplastic (firm, slow-growing, painless, unilateral). The "deep lobe" of the parotid projects medially through the stylomandibular tunnel — deep lobe parotid tumours can present as a pharyngeal mass (visible medially in the throat as a "dumbbell tumour") without obvious external swelling. Increasing swelling with meals (mealtime syndrome) is pathognomonic of salivary duct obstruction by a calculus (sialolithiasis) — the diagnostic mechanism is that eating triggers salivary flow, which cannot drain past the stone, causing acute distension of the duct and gland.

The distinction between allergic angio-oedema (IgE-mediated) and bradykinin-mediated angio-oedema (ACEi-induced or hereditary C1-inhibitor deficiency) is critically important because the treatments are completely different — and standard allergic treatments (antihistamines, corticosteroids) are ineffective for bradykinin-mediated angio-oedema. Allergic angio-oedema: rapid onset with allergen exposure, associated urticaria, responds to adrenaline + antihistamine + corticosteroid. ACEi-induced: can occur any time during ACEi treatment (even years in), predominantly affects lips and tongue (not urticaria), does NOT respond to antihistamines, resolves with ACEi cessation and responds to icatibant (bradykinin receptor antagonist) or C1-inhibitor concentrate. Hereditary angio-oedema (HAE — autosomal dominant C1-INH deficiency): no urticaria, triggers include stress/trauma/oestrogens/dental work, abdominal pain attacks (visceral angio-oedema), family history, normal C4 during attacks excludes most cases of HAE (C4 is chronically low in HAE due to continuous C1 activation). Mumps notification: any suspected mumps must be notified to the local Health Protection Team (HPT) — it is a statutory notifiable disease. Saliva or buccal swab for mumps PCR should be taken before notification. Check MMR vaccination status — the primary vaccine series is 2 doses. Unvaccinated contacts should be offered post-exposure MMR (limited efficacy if already exposed but prevents future susceptibility).

Bimanual palpation of the floor of mouth is the essential examination for detecting submandibular salivary stones — one gloved finger is placed inside the mouth along the floor, and the other hand palpates from externally under the jaw. A stone in Wharton's duct is felt as a hard, non-tender mobile nodule along the duct. Submandibular stones are palpable in 80% of cases. CT is the gold standard imaging (99% sensitivity for all calcified stones) — USS is 90% sensitive but widely available and appropriate first-line. Stensen's duct (parotid) stones are harder to palpate but can be felt at the duct orifice. The OPG (orthopantomogram — panoramic dental X-ray) is the key dental investigation — it shows all teeth, periapical pathology, mandible, maxilla, and can identify salivary calculi. It is arranged via dental practices or oral surgery departments but GPs should specifically request it when dental abscess or salivary stone is suspected. In adults with unexplained unilateral salivary gland swelling, FNA (fine needle aspiration) cytology of the gland is the key investigation for distinguishing inflammatory from neoplastic causes — arranged by oral and maxillofacial surgery (OMFS) or radiology.

The 2WW head and neck cancer pathway has a particularly important role in facial swelling — head and neck cancers collectively represent the sixth most common cancer worldwide. In the UK, the 2WW threshold for head and neck includes any unexplained lump in the neck (especially in patients who smoke or drink alcohol), any unexplained facial or neck swelling persisting >3 weeks, any unilateral persistent parotid or submandibular swelling, and cranial nerve palsies of unexplained cause. Facial cancer (parotid malignancy, SCC of skin, mucosal SCC) often presents as a gradually growing painless facial mass — the painlessness misleads patients and GPs into watchful waiting rather than urgent referral. Key clinical features that raise malignancy concern in facial swelling: non-tender, progressive, firm or hard consistency, skin fixation or ulceration, cranial nerve deficit (facial nerve palsy in parotid cancer = malignant until proven otherwise — facial nerve runs through the parotid), supraclavicular adenopathy, and weight loss. Facial nerve palsy in the context of parotid swelling is a surgical emergency — it indicates malignant nerve invasion, which dramatically worsens prognosis. This must never be attributed to Bell's palsy without a clinical assessment specifically excluding parotid pathology.

The principle that antibiotics alone cannot treat a dental abscess is one of the most important — and most frequently violated — principles in GP antibiotic stewardship. A dental abscess is a closed space infection with a bacterial load of billions of organisms in an avascular, necrotic environment. Antibiotics penetrate avascular tissue poorly and cannot physically drain the pus — the abscess will recur as soon as the antibiotics are discontinued. The definitive treatment is drainage (via tooth extraction, root canal treatment, or incision and drainage) and/or removal of the infected tooth. The GP's role is to provide antibiotics as a temporary bridge to control spreading infection and systemic toxicity while arranging emergency dental care. Prescribing repeated courses of antibiotics for recurrent dental pain without dental referral is a major driver of antibiotic resistance and does not address the underlying problem. Every patient with a dental abscess must be given an urgent dental appointment — NHS 111 provides access to out-of-hours emergency dental services. For the RCGP SCA examination, being able to explain this distinction clearly to a patient who "just wants antibiotics" is a high-yield communication scenario. The icatibant mechanism is important — it is a synthetic decapeptide that competitively antagonises bradykinin B2 receptors, preventing the vasodilation and vascular permeability that bradykinin causes. It is licensed for acute hereditary angio-oedema attacks and is increasingly used for ACEi-induced angio-oedema. It works within 30–60 minutes and is the most effective acute treatment for bradykinin-mediated angio-oedema.

Heerfordt syndrome (uveoparotid fever) is a rare but clinically distinctive manifestation of sarcoidosis — the combination of bilateral parotid swelling, anterior uveitis, facial nerve palsy, and low-grade fever is virtually pathognomonic. It is important for GPs to recognise because it is frequently misdiagnosed: the parotid swelling is attributed to mumps (but it is bilateral, non-tender, and the patient is adult), the facial nerve palsy is attributed to Bell's palsy (but Bell's palsy is unilateral and not accompanied by parotid swelling), and the uveitis may be missed entirely. The combination of these four features should immediately trigger investigation for sarcoidosis: CXR (bilateral hilar lymphadenopathy), ACE level, serum calcium, and IGRA (to exclude tuberculosis as an alternative granulomatous diagnosis). Sjögren's syndrome is one of the most underdiagnosed systemic autoimmune conditions — the average diagnostic delay is 7 years. GPs should think of Sjögren's in any woman over 40 with persistent bilateral parotid swelling, dry eyes, and dry mouth — the combination is specific. The anti-Ro/anti-La antibody screen and referral to rheumatology should be arranged at first clinical suspicion. Sjögren's is associated with a significantly increased risk of B-cell lymphoma (particularly MALT lymphoma in the salivary glands) — 5% lifetime risk — making regular surveillance and referral for any new firm parotid mass in Sjögren's patients mandatory.

The frequency of sugar exposure (not total quantity) is the determinant of dental caries risk — Streptococcus mutans in dental plaque produces acid from sugar within 20 minutes of sugar contact, which demineralises enamel. With very frequent sugar exposure (>7–8 times per day — including sugary drinks, snacks, and fruit juices), the enamel never has time to remineralise (which requires salivary fluoride and a neutral pH). Reducing sugar exposure frequency to 3–4 times per day (meals only, no sugary drinks between meals) dramatically reduces caries risk. This is why continuously sipping sugary drinks is more harmful than having a concentrated sugar dose at a meal. The GP's role in dental prevention — advising about sugar frequency, fluoride toothpaste, and registering with an NHS dentist — is explicitly part of the RCGP curriculum (Making Every Contact Count) and is frequently tested in SCA scenarios. Pilocarpine for Sjögren's xerostomia works by stimulating residual muscarinic M3 receptors in surviving secretory cells — it requires some residual gland function to work. Side effects are cholinergic: sweating, flushing, urinary frequency. It is contraindicated in asthma, narrow-angle glaucoma, and bradycardia. It must be initiated by a specialist (rheumatology or oral medicine) and then continued on GP repeat prescription.

The 48-hour mandatory review for facial cellulitis and dental abscess with swelling is a clinical governance imperative — facial infections are uniquely dangerous because they are in close proximity to the orbit (orbital cellulitis) and the deep fascial planes of the neck and mediastinum (Ludwig's angina → descending necrotising mediastinitis). The progression from dental abscess to Ludwig's angina and from facial cellulitis to orbital cellulitis can occur within 12–24 hours of inadequate treatment. Written safety-netting instructions are essential for all patients with facial swelling managed at home — specifically: "If you develop difficulty opening your mouth, difficulty swallowing, voice changes, or your swelling rapidly increases, call 999 immediately." Head and neck cancer GP co-management is a growing and important part of the GP's role — treatment for head and neck SCC typically involves 6 weeks of concurrent chemoradiotherapy, which causes severe mucositis (Grade 3–4 in 70% of patients), xerostomia, dysphagia, dermatitis, and profound fatigue. GPs manage: pain (opioids, local anaesthetic mouthwashes), nutrition (PEG tube feeding), mucositis (barrier preparations, analgesic gels), psychological distress (IAPT, Macmillan), and late effects (osteoradionecrosis of the mandible — avoid dental extractions without hyperbaric oxygen prophylaxis post-radiotherapy).